Large-scale Molecular Dynamics Simulations Research Articles

Structural stability evolutions of CH4 and CO2 hydrate-sand nanoparticle systems

Despite solid hydrate and mineral particle substances appear extensively in the Earth’s natural environments and engineering applications, physical interactions between hydrates and minerals remain mysterious at the atomic scale due to the experimental challenges at high pressure and low temperature. Herein, particle physical interactions between hydrates and sands are reported using large-scale classical molecular dynamics simulations. Simulation results show that potential energies of nonbonded interactions between different counterparts in hydrate-sand nanoparticle systems exhibit distinctive behaviors, indicative of complex intrinsic interactions among them. Interestingly, both methane and carbon dioxide hydrate nanoparticles are characterized by a thin water layer structure on their surfaces. Molecular structural evolutions of both hydrate and sand nanoparticles are demonstrated in a combination of translational and rotational motions, resulting from van der Waals and Coulombic electrostatic interactions. Moreover, the rotational motion of nanoparticles also depends on thermal fluctuations. Furthermore, hydrate and sand nanoparticles are finally assembled together, accompanied by sintering processes of gas hydrates on sand nanoparticles in good agreement with previous experimental findings. This work quantitatively highlights particle physical interactions between hydrates and sands at the atomic scale, which is of critical importance to understand internal structural evolutions and mechanical stability of gas hydrate systems.

Large-scale atomistic simulation of quantum effects in SrTiO3 from first principles

Quantum effects of lattice vibration play a major role in many physical properties of condensed-matter systems, including thermal properties, such as specific heat, structural phase transition, as well as phenomena, such as quantum crystal and quantum paraelectricity that are closely related to zero-point fluctuations. However, realizing atomistic simulations for realistic materials with a fully quantum-mechanical description remains a great challenge. Here, we propose a first-principles strategy for large-scale molecular dynamics simulation, where a high-accuracy force field obtained by deep-potential (DP) is combined with quantum thermal bath (QTB) method to account for quantum effects. We demonstrate the power of this $\text{DP}+\text{QTB}$ method using the archetypal example $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$, which exhibits several phenomena induced by quantum fluctuations, such as the suppressed structure phase-transition temperature, the quantum paraelectric ground state at low temperatures and the quantum critical behavior $1/{T}^{2}$ law of dielectric constant. Our $\text{DP}+\text{QTB}$ strategy is efficient in simulating large-scale system and is first principles. More importantly, quantum effects of other systems could also be investigated as long as the corresponding DP model is trained. This strategy would greatly enrich our vision and means to study quantum behavior of condensed-matter physics.

A general theory for the bending of multilayer van der Waals materials

Multilayer van der Waals (vdW) materials exhibit nontrivial out-of-plane responses and deformability due to their inherent atomic scale thickness coupled with weak interlayer vdW interactions, which call for a general mechanical framework to quantify such extraordinary characteristics given the structure and material properties. Here, we demonstrate that by considering the competing mechanisms between intralayer stretching, interlayer shearing, and monolayer bending, a general centerline-based theory for multilayered structures is developed to portray the bending landscape of multilayer vdW materials. Combined with large-scale molecular dynamics simulations of three-point bending, we find that when the slenderness ratio or the interlayer shear rigidity is smaller or the intralayer elasticity is higher, the multilayered structures exhibit pronounced nonplanar section deformation due to the interlayer shear capacity. To elucidate quantitative correlations between deformation distribution and structural dimensions and material properties, a critical criterion is proposed to depict the transformation from planar to nonplanar section deformation through a dimensionless characteristic parameter. The effective bending stiffness is then systematically explored in the space of characteristic geometries and material properties to reveal the underlying mechanism of the anomalous size effect. We identify that the effective bending stiffness follows a unified scaling law regarding the dimensionless characteristic parameter. More importantly, a series of deformation-mode phase diagrams are constructed using two universal characteristic lengths, intuitively illustrating the transition of dominated deformation modes and the synergism of geometries and inherent material properties on the bending responses. Validated by several typical vdW materials and novel semiconducting two-dimensional materials, the proposed diagrams not only deepen the understanding of bending in multilayer vdW materials but also provide guidelines for the design and optimization of vdW material-based devices.

Reduced Energy Cost of Ammonia Synthesis Via RF Plasma Pulsing

We have performed an extensive investigation of the parameters affecting the degree of nitrogen fixation and its energy cost in a low-pressure, radio frequency-driven plasma reactor. We find that the hydrogen-to-nitrogen ratio has a strong effect on both the yield and energy cost. A significant degree of nitrogen fixation (∼8%) can be achieved under hydrogen-rich mixtures, but unfortunately these conditions require a higher energy input compared to a one-to-one hydrogen-to-nitrogen ratio. The high degree of nitrogen fixation largely exceeds the degree of nitrogen dissociation in the plasma, suggesting that, while nitrogen dissociation in the plasma likely contributes to the ammonia yield, it cannot account for all of it alone. This confirms the importance of vibrational excitation in this class of processes, as it has been proposed by other research groups. In addition, our study indicates that hydrogen dissociation in the plasma is crucial for stabilizing reaction intermediates. Large-scale ab initio molecular dynamics simulations show that chemisorbed nitrogen is remarkably stable when hydrogen is present at the surface of a metal such as copper, which is otherwise a poor choice of catalyst for a heat-driven catalytic process. Finally, we have found that a pulsed-plasma regime provides a significant improvement in both yield and energy cost. The plasma not only activates surface catalytic processes but also dissociates the produced ammonia when operated in continuous mode. Under a pulsed mode, the plasma is extinguished before ammonia diffuses back into it from the catalyst surface, avoiding the waste of electrical input energy into redissociation of the desired reaction product.

Graphene at Liquid Copper Catalysts: Atomic-Scale Agreement of Experimental and First-Principles Adsorption Height.

Liquid metal catalysts have recently attracted attention for synthesizing high-quality 2D materials facilitated via the catalysts' perfectly smooth surface. However, the microscopic catalytic processes occurring at the surface are still largely unclear because liquid metals escape the accessibility of traditional experimental and computational surface science approaches. Hence, numerous controversies are found regarding different applications, with graphene (Gr) growth on liquid copper (Cu) as a prominent prototype. In this work, novel in situ and in silico techniques are employed to achieve an atomic-level characterization of the graphene adsorption height above liquid Cu, reaching quantitative agreement within 0.1 Å between experiment and theory. The results are obtained via in situ synchrotron X-ray reflectivity (XRR) measurements over wide-range q-vectors and large-scale molecular dynamics simulations based on efficient machine-learning (ML) potentials trained to first-principles density functional theory (DFT) data. The computational insight is demonstrated to be robust against inherent DFT errors and reveals the nature of graphene binding to be highly comparable at liquid Cu and solid Cu(111). Transporting the predictive first-principles quality via ML potentials to the scales required for liquid metal catalysis thus provides a powerful approach to reach microscopic understanding, analogous to the established computational approaches for catalysis at solid surfaces.

The Mechanism of Li Deposition on the Cu Substrates in the Anode-Free Li Metal Batteries.

Due to the rapid growth in the demand for high-energy-density Lithium (Li) batteries and insufficient global Li reserves, the anode-free Li metal batteries are receiving increasing attention. Various strategies, such as surface modification and structural design of copper (Cu) current collectors, have been proposed to stabilize the anode-free Li metal batteries. Unfortunately, the mechanism of Li deposition on the Cu surfaces with the different Miller indices is poorly understood, especially on the atomic scale. Here, the large-scale molecular dynamics simulations of Li deposition on the Cu substrates are performed in the anode-free Li metal batteries. The results show that the surface properties of the Li panel can be altered through the different Cu substrate surfaces. Through surface similarity analysis, potential energy distributions,andinhomogeneousdepositionsimulations,itisfoundthattheLiatomsexhibitdifferentpotential energy variances and kinetic characteristics on the different Cu surfaces. Furthermore, a proposal to reduce the fraction of the (110) facet in commercial Cu foils is made to improve the reversibility and stability of Li plating/stripping in the anode-free Li metal batteries.

Atomistic modeling of tensile deformation and fracture of carbon fibers: Nanoscale stress redistribution, effect of local structural characteristics and nanovoids

The mechanisms of tensile deformation and fracture of carbon fibers are investigated in large-scale molecular dynamics simulations. The simulations performed for computational samples with different structural characteristics enable analysis of the structural sensitivity of the mechanical properties. It is found that the carbon fiber nanostructure can be represented by a fine (nanoscale) mixture of stiff and soft regions. Despite the nanoscale structural heterogeneity of the computational fibers, their fracture strain and tensile strength exceed the experimental values by almost an order of magnitude. This observation is explained by the ability of the carbon fiber nanostructure, largely consisting of curved and folded layers of turbostratic carbon, to exhibit continuous nanoscale load redistribution during the deformation. The transient, fluid nature of a percolating cluster of stress-holding structural elements prevents stress localization at the early stage of the deformation and enables the fiber nanostructure to adapt to the increasing load. Overall, the results of the simulations suggest that the design of advanced carbon fiber manufacturing and post-processing methods focused on the elimination of critical mesoscopic structural defects (internal voids, foreign inclusions, and surface flaws) can yield a substantial increase in the strength and fracture strain of carbon fibers.

SARS-CoV-2 spike opening dynamics and energetics reveal the individual roles of glycans and their collective impact

The trimeric spike (S) glycoprotein, which protrudes from the SARS-CoV-2 viral envelope, binds to human ACE2, initiated by at least one protomer’s receptor binding domain (RBD) switching from a "down” (closed) to an "up” (open) state. Here, we used large-scale molecular dynamics simulations and two-dimensional replica exchange umbrella sampling calculations with more than a thousand windows and an aggregate total of 160 μs of simulation to investigate this transition with and without glycans. We find that the glycosylated spike has a higher barrier to opening and also energetically favors the down state over the up state. Analysis of the S-protein opening pathway reveals that glycans at N165 and N122 interfere with hydrogen bonds between the RBD and the N-terminal domain in the up state, while glycans at N165 and N343 can stabilize both the down and up states. Finally, we estimate how epitope exposure for several known antibodies changes along the opening path. We find that the BD-368-2 antibody’s epitope is continuously exposed, explaining its high efficacy.

Mechanistic Insights into the Protection Effect of Argonaute-RNA Complex on the HCV Genome.

While host miRNA usually plays an antiviral role, the relentless tides of viral evolution have carved out a mechanism to recruit host miRNA as a viral protector. By complementing miR-122 at the 5' end of the genome, the hepatitis C virus (HCV) gene can form a complex with Argonaute 2 (Ago2) protein to protect the 5' end of HCV RNA from exonucleolytic attacks. Experiments showed that the disruption of the stem-loop 1(SL1) structure and the 9th nucleotide (T9) of HCV site 1 RNA could enhance the affinity of the Ago2 protein to the HCV site 1 RNA (target RNA). However, the underlying mechanism of how the conformation and dynamics of the Ago2: miRNA: target RNA complex is affected by the SL1 and T9 remains unclear. To address this, we performed large-scale molecular dynamics simulations on the AGO2-miRNA complex binding with the WT target, T9-abasic target and SL1-disruption target, respectively. The results revealed that the T9 and SL1 structures could induce the departing motion of the PAZ, PIWI and N domains, propping up the mouth of the central groove which accommodates the target RNA, causing the instability of the target RNA and disrupting the Ago2 binding. The coordinated motion among the PAZ, PIWI and N domains were also weakened by the T9 and SL1 structures. Moreover, we proposed a new model wherein the Ago2 protein could adopt a more constraint conformation with the proximity and more correlated motions of the PAZ, N and PIWI domains to protect the target RNA from dissociation. These findings reveal the mechanism of the Ago2-miRNA complex's protective effect on the HCV genome at the atomic level, which will offer guidance for the design of drugs to confront the protection effect and engineering of Ago2 as a gene-regulation tool.

Gold nanoparticle design for RNA compaction.

RNA-based therapeutics hold a great promise in treating a variety of diseases. However, double-stranded RNAs (dsRNAs) are inherently unstable, highly charged, and stiff macromolecules that require a delivery vehicle. Cationic ligand functionalized gold nanoparticles (AuNPs) are able to compact nucleic acids and assist in RNA delivery. Here, we use large-scale all-atom molecular dynamics simulations to show that correlations between ligand length, metal core size, and ligand excess free volume control the ability of nanoparticles to bend dsRNA far below its persistence length. The analysis of ammonium binding sites showed that longer ligands that bind deep within the major groove did not cause bending. By limiting ligand length and, thus, excess free volume, we have designed nanoparticles with controlled internal binding to RNA's major groove. NPs that are able to induce RNA bending cause a periodic variation in RNA's major groove width. Density functional theory studies on smaller models support large-scale simulations. Our results are expected to have significant implications in packaging of nucleic acids for their applications in nanotechnology and gene delivery.

Misorientation-dependent transition between grain boundary migration and sliding in FCC metals

Grain boundaries (GBs) play a crucial role in the mechanical behaviors of nanocrystalline materials. The dynamics of GBs depend on a variety of intrinsic and extrinsic factors, including GB misorientation, inclination, curvature, metal type and loading history. Controlling GB geometry and deformation behavior thus provides effective means to tailor the mechanical properties of nanostructured materials. However, the relationship between deformation mechanism and GB geometry is still lacking, largely due to the vast amount of metastable GB structures and deformation paths. Here, the relation between GB misorientation (θ, a critical degree of freedom for GB structure) and GB deformation mechanisms was studied by large-scale molecular dynamic simulation in face-centered cubic (FCC) metals. With increasing GB misorientation, the GB deformation mechanism transitions from migration to sliding and further to migration again. The critical transition thresholds (critical misorientations) vary with metal types. An energetic model that links deformation mechanism with GB structure was further developed with a focus on predicting the critical GB misorientation at which GB sliding supersedes GB migration. The influence of metal type on the transition threshold is well captured. We finally extend this model to general GBs with complex atomic structures and compare the theoretical predictions with data reported in the literatures and obtained from the present work. Our findings shed lights on the misorientation-dependent GB deformation mechanisms and can be utilized in GB engineering that pursues high-performance nanocrystalline metals.

An interfacial gas-enrichment strategy for mitigating hydrate adhesion and blockage

Unwanted gas hydrates blockage is a threat to the safety of oil–gas pipeline systems. Deploying passive anti-hydrate surfaces is a promising approach to circumventing the long-lasting hydrate problem, and a precise understanding of the interactions between hydrate and solid surfaces is a prerequisite for the creation of such surfaces. In this work, the underlying mechanisms and the key influencing factors of hydrate adhesion are explored by large-scale molecular dynamics simulations. Hydrates with an intermediate layer (IML) containing varied gas content are brought to contact with solid surfaces having different levels of wettability and roughness. It is found that the final IML structure is dictated by the gas concentration. Enriching gas content in the vicinity of solid surfaces is crucial for lowering hydrate adhesion strength. The results indicate that forming a molecular gas layer or gas bubbles on solid surfaces can enable the automatic detachment of the eventually formed hydrate on a pipeline wall surface under the action of shear flow. This study manifests our approach of utilizing an interfacial gas-enrichment strategy (IGES) for weakening hydrate adhesion as a novel passive anti-hydrate surface design.

Abnormal hardening and amorphization in an FCC high entropy alloy under extreme uniaxial tension

Ever more extreme environments in advancing industrial applications motivate efforts to design new generation of alloys with excellent mechanical properties. High entropy alloys (HEAs) are considered as promising candidates for bearing extreme loadings. However, the reported results of correspondence between extremely mechanical behaviors and micromechanisms are still in infancy. Here we showed mechanical responses over wide strain rate and temperature ranges and microscopic observations recovered from dynamic uniaxial tension of face-centered cubic (FCC) HEA to reveal plasticity mechanisms transition under various loading conditions. In particular, with an increasing strain during the extreme dynamic tension a sequence of mechanisms, including twinning, detwinning-induced localization, nanoscale body-centered cubic (BCC) phase transformation and symbiotic amorphization, were progressively activated for continued plasticity. At strains over 35%, twin boundaries hindrance to localized band propagation and more dislocations emitting from BCC phases even collectively caused a second sharp rise in hardening. Additionally, the plasticity kept increasing during crystal to amorphization transition, which should be promoted by severe lattice distortion in super-dense dislocations areas. By combining large scale molecular dynamic simulations, the causes of phase transition to BCC lattice structure or even to amorphous bands were explained in depth. The thorough uncovering of these brand-new mechanisms can help understand the plasticity and amorphization of HEAs under the extreme loadings.

Quasiplastic deformation in shocked nanocrystalline boron carbide: Grain boundary sliding and local amorphization

Materials respond to shock in many ways such as plastic flow in metals and amorphization in ceramics. It is very challenging to characterize the deformation mechanisms of ceramics under shock compression due to extreme loading conditions. Here we report the shock response of nanocrystalline boron carbide (n-B4C) using large-scale molecular dynamics simulations with a machine-learning force field. We identify three quasiplastic deformation mechanisms in shocked n-B4C: grain boundary (GB) sliding, intergranular amorphization, and intragranular amorphization. As the deformation mechanism changes from GB sliding to intergranular amorphization at ∼40 GPa, a bilinear Hugoniot behavior occurs, consistent with experimental observations. At higher pressure (>∼100 GPa), intragranular amorphization becomes dominant, causing a complete loss of shear strength. These quasiplastic mechanisms may play an important role in the shock behaviors of ceramics.

Tailoring small-scale plasticity of nanotwined-copper micropillars via microstructures

Nanotwined (nt) copper is attractive in applications such as microbumps in the microelectronics industry because nt-copper presents sound mechanical and physical properties. To date, most studies of the mechanical properties of nt-copper have been performed at macroscales. However, different stories are told at micro/nanoscales, e.g., smaller size leads to higher strength. Understanding the mechanical properties of nt-copper at micro/nanoscales is crucial for improving the reliability and endurability of microdevices. In this paper, we fabricated nt-copper film with tailored microstructures, i.e., twin boundaries (TBs) with different spacings and orientations (parallel or slanted to loading direction). Then, we applied micro-compression testing, atomistic simulation, and theoretical analysis to investigate the influence of vertical twin-boundary spacing λ and orientation on the deformation behavior of nt-micropillars. Results show that the yield stress is increased with decreasing vertical λ. Micropillars with slanted λ = 15.5 nm TBs present the greatest strength, which may be attributed to a finer λ. The phenomenon, strength increasing with decreasing λ, was well explained by the Hall–Petch and confined layer slip models. Large-scale molecular dynamics simulations were used to uncover the atomistic and real-time deformation mechanisms. This microscale research on nt-micropillars may provide insights on designing advanced microelectronics.

Tensile and Viscoelastic Behavior in Nacre-Inspired Nanocomposites: A Coarse-Grained Molecular Dynamics Study.

Organisms hold an extraordinarily evolutionary advantage in forming complex, hierarchical structures across different length scales that exhibit superior mechanical properties. Mimicking these structures for synthesizing high-performance materials has long held a fascination and has seen rapid growth in the recent past thanks to high-resolution microscopy, design, synthesis, and testing methodologies. Among the class of natural materials, nacre, found in mollusk shells, exhibits remarkably high mechanical strength and toughness. The highly organized “brick and mortar” structure at different length scales is a basis for excellent mechanical properties and the capability to dissipate energy and propagation in nacre. Here, we employ large-scale atomistic coarse-grained molecular dynamics simulations to study the mechanical and viscoelastic behavior of nacre-like microstructures. Uniaxial tension and oscillatory shear simulations were performed to gain insight into the role of complex structure-property relationships. Specifically, the role played by the effect of microstructure (arrangement of the crystalline domain) and polymer-crystal interactions on the mechanical and viscoelastic behavior is elucidated. The tensile property of the nanocomposite was seen to be sensitive to the microstructure, with a staggered arrangement of the crystalline tablets giving rise to a 20–30% higher modulus and lower tensile strength compared to a columnar arrangement. Importantly, the staggered microstructure is shown to have a highly tunable mechanical behavior with respect to the polymer-crystal interactions. The underlying reasons for the mechanical behavior are explained by showing the effect of polymer chain mobility and orientation and the load-carrying capacity for the constituents. Viscoelastic responses in terms of the storage and loss moduli and loss tangent are studied over three decades in frequency and again highlight the differences brought about by the microstructure. We show that our coarse-grained models offer promising insights into the design of novel biomimetic structures for structural applications.

Inverse Hall–Petch effect in nanocrystalline ice predicted by machine-learned coarse-grained molecular simulations

We study the grain-size effect on mechanical behaviors of polycrystalline ice at nanoscale through large-scale molecular dynamics simulations, enabled by an accurate and efficient machine-learned coarse-grained water model [H. Chan, M. J. Cherukara, B. Narayanan, T. D. Loeffler, C. Benmore, S. K. Gray and S. K. Sankaranarayanan. Machine learning coarse grained models for water. Nature Communications 10(1), p. 379, 2019]. Polycrystalline ice systems with different grain sizes in the range of [Formula: see text][Formula: see text]nm are systematically investigated through uniaxial tensile tests. Simulation results reveal that Young’s modulus and yield strength increase as the grain size increases, leading to an inverse Hall–Petch effect in nanocrystalline ice. Such an observation is significantly different from the conventional Hall–Petch effect in polycrystalline ice observed by experiments at millimeter scale. The deformation behavior suggests that grain boundaries (GBs), rather than grain interiors, play the active role in accommodating external loading in nanocrystalline ice. Further void analysis of nanocrystalline ice during deformation reveals that nanocrack initiates and propagates along GBs and eventually leads to failure of systems with larger grain sizes ([Formula: see text][Formula: see text]nm), yielding a sudden drop in the stress–strain curve. While for systems with smaller grain sizes ([Formula: see text][Formula: see text]nm), only extensive plastic deformation is presented without significant void growth. Our simulation results demonstrate that the GB sliding is the governing mechanism for the inverse Hall–Petch effect observed in nanocrystalline ice.

Topologically close-packed structure characteristics of the plastic deformation regions of amorphous Cu64.5Zr35.5

Understanding the structure of the plastic deformation region is important for improving the mechanical property of amorphous alloys. What kind of structure is conducive to the formation of deformation zone is however still unclear yet. The uniaxial compression of amorphous Cu64.5Zr35.5 has been conducted by a large-scale molecular dynamics simulation. The structure characteristics of the system, especially the deformation regions are systematically investigated based on the newly developed topologically close-packed cluster (TCP) method and the shear transformation zone theory. Results indicate that the deformation process is divided into three stages that can be reasonably explicated by the population and heredity of the 30 top largest standard clusters (LaSCs). It is also found that the response of topologically close-packed (TCP) atoms to strain is closely related with the bond number connected to icosahedra atoms, and the densely packed TCP atoms are more prone to non-affine displacement than the loosely packed ones, which act as the carrier of accommodating plastic deformation. In addition, the plastic deformation units are composed of various types of LaSCs, and the region with local translational symmetry is observed. These findings greatly improve the understanding of the relationship of microstructure and deformation of metallic glasses.

Nanoporous Membranes of Densely Packed Carbon Nanotubes Formed by Lipid-Mediated Self-Assembly.

Nanofiltration technology faces the competing challenges of achieving high fluid flux through uniformly narrow pores of a mechanically and chemically stable filter. Supported dense-packed 2D-crystals of single-walled carbon nanotube (CNT) porins with ∼1 nm wide pores could, in principle, meet these challenges. However, such CNT membranes cannot currently be synthesized at high pore density. Here, we use computer simulations to explore lipid-mediated self-assembly as a route toward densely packed CNT membranes, motivated by the analogy to membrane-protein 2D crystallization. In large-scale coarse-grained molecular dynamics (MD) simulations, we find that CNTs in lipid membranes readily self-assemble into large clusters. Lipids trapped between the CNTs lubricate CNT repacking upon collisions of diffusing clusters, thereby facilitating the formation of large ordered structures. Cluster diffusion follows the Saffman-Delbrück law and its generalization by Hughes, Pailthorpe, and White. On longer time scales, we expect the formation of close-packed CNT structures by depletion of the intervening shared annular lipid shell, depending on the relative strength of CNT-CNT and CNT-lipid interactions. Our simulations identify CNT length, diameter, and end functionalization as major factors for the self-assembly of CNT membranes.

Mechanistic Understanding of the Palmitoylation of Go Protein in the Allosteric Regulation of Adhesion Receptor GPR97

Adhesion G-protein-coupled receptors (aGPCRs)—a major family of GPCRs—play critical roles in the regulation of tissue development and cancer progression. The orphan receptor GPR97, activated by glucocorticoid stress hormones, is a prototypical aGPCR. Although it has been established that the palmitoylation of the C-terminal Go protein is essential for Go’s efficient engagement with the active GPR97, the detailed allosteric mechanism remains to be clarified. Hence, we performed extensive large-scale molecular dynamics (MD) simulations of the GPR97−Go complex in the presence or absence of Go palmitoylation. The conformational landscapes analyzed by Markov state models revealed that the overall conformation of GPR97 is preferred to be fully active when interacting with palmitoylated Go protein. Structural and energetic analyses indicated that the palmitoylation of Go can allosterically stabilize the critical residues in the ligand-binding pocket of GPR97 and increase the affinity of the ligand for GPR97. Furthermore, the community network analysis suggests that the palmitoylation of Go not only allosterically strengthens the internal interactions between Gαo and Gβγ, but also enhances the coupling between Go and GPR97. Our study provides mechanistic insights into the regulation of aGPCRs via post-translational modifications of the Go protein, and offers guidance for future drug design of aGPCRs.