L-arginine Phosphate Monohydrate Research Articles

Investigations on aqueous solution grown l-Arginine Phosphate monohydrate (LAP) single crystals for efficient THz generation

Single crystals of l-arginine phosphate monohydrate (LAP) with dimensions of 15 × 10 × 3.5 mm3 were grown by solution cooling method from its aqueous solution. The crystalline phase formation of the synthesized LAP was confirmed using powder X-ray diffraction measurements. Typical morphology of the spontaneously grown LAP crystal was ascertained through optical microscope. The LAP crystal was explored for its ability to generate Terahertz waves by employing a Ti: sapphire laser of 800 nm wavelength, 140 fs pulses, at 80 MHz repetition rate. It is reported, for the first time to the best of our knowledge, that the LAP crystal was capable of generating THz radiation in the range between 0.1 and 2.0 and that there was a gradual enhancement of the THz output power when the input power was increased from 500 to 1200 mW. The optical to THz conversion efficiency of LAP crystal was measured to be about 0.7 × 10−5 which is considerably higher than the well-known inorganic material ZnTe, even with its larger area. Further, the refractive index and absorption coefficient measured for the crystal were found to vary between 1.2 and 1.65 and 5 and40 cm−1 respectively in the range between 0.1 and 2.0 THz. The coherence length of the LAP was theoretically calculated to be about 400 mm at 0.8 THz.

Study of the hyper-Rayleigh scattering first hyperpolarizability of a chalcone derivative in various solvent media

In this work we investigate the solvent media effects on the nonlinear optical properties of a chalcone derivative, (2E)-3-(3-methylphenyl)-1-(4-nitrophenyl) prop-2-en-1-one (3MPNP), using the polarizable continuum model (PCM) at DFT/B3LYP/6-311+G(d) level. The behavior of the hyper-Rayleigh scattering first hyperpolarizability and the average second hyperpolarizability, are studied as function of the dielectric constant of the solvent medium in both dynamic and static cases. Full Text: PDF ReferencesL. R. Almeida et al., "Synthesis, structural characterization and computational study of a novel amino chalcone: a potential nonlinear optical material", New J. Chem., vol. 41, no. 4, pp. 1744-1754, 2017. CrossRef P. K. Murthy et al., "An analysis of structural and spectroscopic signatures, the reactivity study of synthetized 4,6-dichloro-2-(methylsulfonyl)pyrimidine: A potential third-order nonlinear optical material", J. Mol. Struct., vol. 1186, pp. 263-275, Jun. 2019. CrossRef J. Kongsted, A. Osted, K. V Mikkelsen, and O. Christiansen, "“Second harmonic generation second hyperpolarizability of water calculated using the combined coupled cluster dielectric continuum or different molecular mechanics methods", J. Chem. Phys., vol. 120, no. 8, pp. 3787-98, Feb. 2004. CrossRef T. L. Fonseca, J. R. Sabino, M. A. Castro, and H. C. Georg, "A theoretical investigation of electric properties of L-arginine phosphate monohydrate including environment polarization effects", J. Chem. Phys., vol. 133, no. 14, pp. 1-8, 2010. CrossRef A. KARAKAŞ, Z. E. KOÇ, M. FRIDRICHOVÁ, P. NĚMEC, and J. KROUPA, "THE INVESTIGATION OF SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF P-NITROPHENYLAZOANILINE: SECOND HARMONIC GENERATION AND AB INITIO COMPUTATIONS", J. Theor. Comput. Chem., vol. 11, no. 01, pp. 209-221, Feb. 2012. CrossRef T. Seidler, K. Stadnicka, and B. Champagne, "Second‐order Nonlinear Optical Susceptibilities and Refractive Indices of Organic Crystals from a Multiscale Numerical Simulation Approach", Adv. Opt. Mater., vol. 2, no. 10, pp. 1000-1006, Oct. 2014. CrossRef L. M. G. Abegão et al., "Second- and third-order nonlinear optical properties of unsubstituted and mono-substituted chalcones", Chem. Phys. Lett., vol. 648, pp. 91-96, Mar. 2016. CrossRef W. F. Vaz et al., "Synthesis, characterization, and third-order nonlinear optical properties of a new neolignane analogue", RSC Adv., vol. 6, no. 82, pp. 79215-79227, 2016. CrossRef C. Valverde et al., "The solid state structure and environmental polarization effect of a novel asymmetric azine", New J. Chem., vol. 41, no. 19, pp. 11361-11371, 2017. CrossRef P. N. Prasad, D. J. Williams, and others, Introduction to nonlinear optical effects in molecules and polymers, vol. 1. Wiley New York etc., 1991. DirectLink P. Günter, Nonlinear Optical Effects and Materials, 4th ed. Berlin: Springer Berlin Heidelberg, 2000. CrossRef H. Inan et al., "Photonic crystals: emerging biosensors and their promise for point-of-care applications", Chem. Soc. Rev., vol. 46, no. 2, pp. 366-388, 2017. CrossRef H. J. Chang et al., "Chiral Nonlinear Optics in Oxides, Polymers and Liquid Crystals", J. Korean Phys. Soc., vol. 43, no. 4, p. 587, 2003. DirectLink R. Bersohn, Y. Pao, and H. L. Frisch, "Double‐Quantum Light Scattering by Molecules", J. Chem. Phys., vol. 45, no. 9, pp. 3184-3198, Nov. 1966. CrossRef K. Clays and A. Persoons, "Hyper-Rayleigh scattering in solution", Phys. Rev. Lett., vol. 66, no. 23, pp. 2980-2983, 1991. CrossRef J. Campo, F. Desmet, W. Wenseleers, and E. Goovaerts, "Highly sensitive setup for tunable wavelength hyper-Rayleigh scattering with parallel detection and calibration data for various solvents", Opt. Express, vol. 17, no. 6, p. 4587, Mar. 2009. CrossRef S. R. Prabhu, A. Jayarama, K. Chandrasekharan, V. Upadhyaya, and S. W. Ng, "Synthesis, growth, structural characterization, Hirshfeld analysis and nonlinear optical studies of a methyl substituted chalcone", J. Mol. Struct., vol. 1136, pp. 244-252, May 2017. CrossRef K. Clays and A. Persoons, "Hyper‐Rayleigh scattering in solution", Rev. Sci. Instrum., vol. 63, no. 6, pp. 3285-3289, Jun. 1992. CrossRef K. Clays et al., "Nonlinear Optical Properties of Proteins Measured by Hyper-Rayleigh Scattering in Solution", Science (80-. )., vol. 262, no. 5138, pp. 1419-1422, Nov. 1993. CrossRef M. Frisch et al., Gaussian, Inc., Wallingford CT, 2009. DirectLink J. M. F. Custodio et al., "Chalcone as Potential Nonlinear Optical Material: A Combined Theoretical, Structural, and Spectroscopic Study", J. Phys. Chem. C, vol. 123, no. 10, pp. 5931-5941, Mar. 2019. CrossRef

Electronic structure and optical properties of phosphate bis-guanidinoacetate crystal containing guanidine phosphate interaction

L-arginine phosphate monohydrate (LAP) crystal is an excellent nonlinear optical material, its effective nonlinear optical coefficient is about 2−3.5 times that of potassium dideuterium phosphate (KDP) crystal, and its conversion efficiency can achieve up to 90%. The deuterated crystal of LAP has a very high laser damage threshold. Thus, once it was considered as a preferred material to replace KDP crystal for laser inertial confinement fusion and other fields. In addition, the LAP crystal has a much higher stimulated Brillouin scattering (SBS) reflectivity than quartz crystal and also has a lower SBS threshold. Moreover, it exhibits a special reversible phase-change in the variable temperature process, and shows an ultra-long spin-lattice relaxation time at solid-state NMR. In a word, the LAP crystal has shown its uniqueness under the action of energy such as light, heat and magnetic field. However, for these special phenomena, there is no reasonable explanation. Phosphate arginine is responsible for the biological energy storage and transfer in invertebrates as an important phosphorus source, which has a similar chemical composition to that of LAP crystal. The special electrostatic or hydrogen bonding interaction between guanidine and phosphate plays an important role in protein molecule interaction and their biochemical functions. Moreover, the conformational transitions of L-arginine molecule in phosphoric acid solution at different energies have been reported, and the fluorescence emission of L-arginine molecule aggregates can be changed by the interaction between phosphoate and guanidine group. The interaction between phosphoate and guanidine group in crystal structure is also studied as a model of biomolecular interaction. In order to further study the mechanism of interaction between phosphoate and guanidine group and the crystal macroscopic properties, phosphate bis-guanidinoacetate (PBGA) crystal containing the similar phosphoate and guanidine groups has been synthesized and reported. In this paper, the geometry parameters, band structure, electronic density of states, and optical properties of PBGA crystal are investigated by first-principles based the density functional theory. The energy gap of PBGA crystal is 4.77 eV, much smaller than 5.96 eV of KDP crystal. Therefore, the photon transition becomes easier and the corresponding photon absorption is relatively large in PBGA crystal. The top states of crystal valence band are mainly composed of the N-2p of guanidine and the O-2p of carboxyl and phosphate groups. There exists the electron interaction among guanidine, carboxyl and phosphate groups. The optical properties of PBGA crystal are similar in the [100] and [010] orientation, whose linear optical properties are better than those of [001] when the incident photon energy is less than 10 eV. The strong energy loss peak at 9.46 eV in the [001] orientation is due to the electronic transition of N-2p on guanidine group in the valence band, and its distribution is narrow. Thus the optical properties of [001] orientation are limited. The present research establishes a good foundation for further understanding and studying the intergroup interactions and optical properties in PBGA crystal.

Crystal growth and optical characterization of chromium-doped l-arginine phosphate monohydrate

l-arginine phosphate monohydrate single crystals doped with Cr3+ ions (LAP:Cr) were grown by slow cooling method, with dimensions up to 10 × 10 × 8 mm3. Chromium ions induce a drastic reduction of overall growth rate and produce a drastic change in LAP growth morphology. The functional groups of LAP:Cr crystals were confirmed by FTIR analysis and compared with pure LAP. The optical band gap of LAP:Cr was determined from UV-VIS-NIR transmittance spectrum. Optical absorption spectrum at room temperature and 10 K was measured consisting of two large bands due to the 4A2 → 4T2 and 4A2 → 4T1 transitions and a narrower band attributed to the 4A2 → 2E spin-forbidden transition, characteristic of Cr3+ ions. Luminescence spectra of pure and Cr3+-doped samples were collected with excitation at wavelength of 350 nm and 335 nm. Emissions from host LAP matrix and Cr3+ ions were observed. Excited with 350 nm the spectra reveal a broad intense band from 21000 to 26000 cm−1 region due to electronic transition from LAP ligand. The emission spectra of doped sample present two broad bands centered at 12346 cm−1 and 13412 cm−1 from 2E → 4A2 and 4T2 → 4A2 transitions, characteristics of luminescence from Cr3+ ions. From these results the Racah and crystal-field Cr3+ parameters were evaluated and comparing with those obtained in similar systems.

Effect of the crystalline environment on the third-order nonlinear optical properties of L-arginine phosphate monohydrate: a theoretical study.

A supermolecular approach combined with an iterative electrostatic scheme was employed to investigate the nonlinear optical properties of the hybrid L-arginine phosphate monohydrate crystal, the procedure being aided by DFT calculations. The supermolecular scheme basically treated the molecules surrounding the unit cell as point charges; this approximation results in rapid convergence, making it a feasible method. DFT functionals of different flavors were considered: B3LYP, B2PLYP, CAM-B3LYP, ωB97, and M06HF, utilizing the 6-311 + G(d) basis set. All functionals gave sufficiently accurate values for the dipole moment (μ) with respect to the experimental value 32(2)D. For the average linear polarizability ([Formula: see text]) and the total first hyperpolarizability (β tot), good agreement was observed between the DFT-calculated values and MP2-derived results reported in the literature. For the second hyperpolarizability, both static and dynamic regimes were considered. The point-charge embedding approach led to an attenuation of the second hyperpolarizability γ for all frequencies considered. Excitations of γ were not observed for frequencies smaller than 0.1a.u. For the second hyperpolarizability (both static and dynamic), computational results showed that L-arginine phosphate monohydrate exhibits a large nonlinear optical effect, which implies the occurrence of microscopic third-order NLO behavior.

Influence of urea doping on optical, thermal, mechanical and electrical properties of l-arginine phosphate monohydrate crystals for NLO applications

In the present investigation, the influence of urea doping on the optical, structural, thermal, mechanical and dielectric properties of l-arginine phosphate monohydrate (LAP) crystal were investigated. Pure and doped LAP crystals were grown from aqueous solution by evaporating solvent at a constant temperature. The presence of dopant was confirmed qualitatively by FT-IR spectroscopy. Powder X-ray diffraction study reveals slight modification in lattice parameters of doped crystal. Ultraviolet–visible–near infrared transmission study reveals increase in optical transparency and band gap of doped crystals with doping concentration. Other optical parameters such as refractive index, extinction coefficient, reflectance, optical and electrical conductivity of pure and doped crystals were evaluated from transmission spectrum only. Noticeable enhancement in second harmonic generation efficiency (1.67 times more) has been observed for 1mol percent urea doped LAP crystal as compare to pure one. Doped LAP crystals show higher mechanical and thermal stabilities than pure LAP crystal. Electrical properties like as dielectric constant, dielectric loss, ac conductivity and activation energy were also studied.

Guanidine-phosphate non-covalent interaction in LAP crystal growth solution evidenced from spectroscopy studies

The similar l-arginine molecule aggregation has been found in l-arginine (LA) and l-arginine phosphate monohydrate (LAP) aqueous solutions. The special fluorescence emission at 380nm of LA aggregates in LAP solution has been found, compared with the emission of LA solution at 415nm, which has an obvious blue shift. By comparing the fluorescence spectra of several solutions for l-arginine and l-lysine salts, the interaction between phosphate and guanidine in LAP solution was considered to be the cause of its special fluorescence emission. Meanwhile, when LAP molecule formed in solution, the fluorescence emission wavelength and the UV absorption intensity at 296nm of l-arginine solutions have mutated. Therefore, the group interaction involved by guanidine has changed the fluorescence properties of l-arginine aggregates in LAP solution, indicating that the specific interaction between phosphate and guanidine exists in LAP molecule.

Novel Study on Determination of Crystal Growth Conditions for L-arginine Phosphate Monohydrate Crystal by Ultrasonic Velocity Measurement in Aqueous Solution of L-arginine and Phosphoric Acid

Low temperature solution growth technique is a versatile and low cost technique to grow single crystals of good quality. Before crystal growth, it needs to decide solvent and growth temperature by studying solubility at different temperatures in different solvents, and pH of the growth solution. Metastable zone width and induction period are other important parameters considered during crystal growth. We have presented a simple, cost effective test to decide growth temperature, solution pH and proportion of different components (in case of multi-component compounds) of compound in the solution to grow quality single crystals with optimum growth rate. L-arginine phosphate monohydrate is a promising nonlinear optical crystal and we have successfully attempted to study the optimum pH and proportion of L-arginine and phosphoric acid in the solution for crystal growth by measuring ultrasonic velocity and determining related thermodynamic parameters.

Investigation on Relationship Between Energy Storage and Special Performance of L-arginine Phosphate Monohydrate (LAP) Crystal

Phosphate arginine (PA) has been known as the medium carriers for bioenergy storage, while the similar structural substance L-arginine phosphate monohydrate (LAP) crystal is an excellent nonlinear optical crystal with a high laser-induced damage threshold. Energy storage in organism and laser-induced damage in crystals are both correlative to energy. Temperature dependence X-ray diffraction (XRD) and solid state NMR spectroscopy were performed to explore the impact of energy (heat and magnetic) fields on LAP crystal. XRD results reveal that LAP processes a reversible specific phase transition as the temperature changed. Saturation recovery experiments have shown that the crystal has a long proton spin-lattice relaxation time (1H T1) of 184 s with an amazing solid-state stability. The nuclear magnetic resonance (NMR) and fluorescence emission spectra of LAP solution compared with several amino salt solutions have also been investigated. The results show that the emission wavelength of LAP solution is blue-shifted from 415 to 380 nm. When energy (laser, heat, magnetic and etc.) fields are applied on LAP crystal, it processes a various of distinctive properties which make LAP a special material worthy of further detailed investigation.

Does an ‘l-arginine doped orthophosphoric acid’ crystal exist?

The reactive nature of aqueous orthophosphoric acid (H3PO4) towards l-arginine (l-Arg), to form a phosphate salt namely l-arginine phosphate monohydrate (LAP), rules out the doping of any l-arginine into H3PO4. Hence, the reported claim of growth of ‘l-arginine doped orthophosphoric acid’ crystals by Saradha et al. J. Lumin (2013) is untenable.

Growth and characterization of potassium halides mixed l-arginine phosphate monohydrate semi organic nonlinear optical single crystals

Single crystals of pure and potassium halides additive mixed l-arginine phosphate monohydrate have been grown with good optical quality by slow temperature reduction method. Microbial growth aspects and coloration have been studied on the growth solutions. In addition to that the structural properties have been studied by powder X-ray diffraction method and Fourier transform infrared spectral analyses for the grown crystals. Thermal stability of the grown crystals were studied by thermo gravimetric (TG) and differential thermal analyses (DTA) and found that the grown crystals are suitable for device fabrication for frequency conversion applications.

Study on effect of 1,3-dimethyl urea doping on optical properties of l-arginine phosphate monohydrate (LAP) single crystal

Pure and 1,3-dimethyl urea doped l-arginine phosphate monohydrate (LAP) crystals were grown by a solution growth technique from aqueous solution at a constant temperature. The effect of dopant on the optical properties, crystal structure and second harmonic generation (SHG) efficiency was studied. Dopant modifies the SHG efficiency of the LAP crystal at a greater extent. The SHG efficiency of 0.01mol% 1,3-dimethyl urea doped LAP crystal corresponds to 1.37 times more as compared to the pure LAP. Absorption and transmission were measured in the spectral range 190–1083nm. The increase in the optical transparency of the doped crystal is reported. The band gap of the grown crystals has been determined. The presence of the dopant in the doped crystals was confirmed qualitatively by the FT-IR spectroscopy. A slight variation in unit cell parameters has been reported. Thermal and dielectric study of the doped crystal has also been presented.

Unidirectional crystal growth and crystalline perfection ofL-arginine phosphate monohydrate

A large (∼20 mm diameter and 80 mm length) single crystal of L-arginine phosphate monohydrate (LAP) has been grown for the first time by the unidirectional Sankaranarayanan–Ramasamy method in an aqueous medium in a specially designed constant-temperature bath. The crystal structure has been confirmed by powder X-ray diffraction. The crystalline perfection was assessed by high-resolution X-ray diffractometry (HRXRD) which found that the quality of the grown single crystal is quite good. HRXRD studies along different directions show that the crystal contains a low density of edge-type dislocations formed along the growth direction. The thermal stability was assessed using thermogravimetric/differential thermal analysis. The mechanical behaviour was studied using an Omnitech micro-hardness tester. The dielectric studies were carried out over a wide frequency range of 10 Hz to 5 MHz at room temperature. The characterization studies reveal that the grown bulk single crystal of LAP is suitable for device applications.

Crystal growth, structural and thermal studies of amino acids admixtured l-arginine phosphate monohydrate single crystals

To study the improved characteristics of l-arginine phosphate monohydrate (LAP) crystals, amino acids mixed LAP crystals have been grown by slow cooling method. Amino acids like glycine, l-alanine, and l-valine have been selected for doping. Optical quality bulk crystals have been harvested after a typical growth period of about twenty days. The effect of amino acids in the crystal lattice and molecular vibrational frequencies of various functional groups in the crystals have been studied using X-ray powder diffraction and Fourier Transform infrared (FTIR) analyses respectively. Thermal behavior of the amino acids mixed LAP crystals have been studied from the TG and DTG analyses. High-resolution X-ray diffraction studies have been carried out to find the crystalline nature. Optical transmission studies have been carried out by UV–vis spectrophotometer. The cut off wavelength is below 240 nm for the grown crystals.

Characterization studies on the additives mixed l-arginine phosphate monohydrate (LAP) crystals

l-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP (LAP:Na 2SO 3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.

A theoretical investigation of electric properties of L-arginine phosphate monohydrate including environment polarization effects

The dipole moment (μ), linear polarizability (α), and first hyperpolarizability (β(tot)) of the asymmetric unit of L-arginine phosphate (LAP) monohydrate crystal are investigated using the supermolecule approach in combination with an iterative electrostatic polarization scheme. Environment polarization effects are attained by assuring the convergence of the dipole moment of LAP embedded in the polarization field of the surrounding molecules whose atomic sites are treated as point charges. The results obtained show that in the presence of the embedding charges, the value of μ is increased by 9% but the static values of α and β(tot) are decreased, respectively, by 3% and 13%, as compared with the isolated situation. The MP2/6-311+G(d) model predicts for the in-crystal dipole moment the converged value of 33 D, in good concordance with the available experimental result of 32 D. Our estimates for the converged results of α and β(tot) are, respectively, 22.51×10(-24) and 5.01×10(-30) esu. Dispersion effects are found to have a small impact on the nonlinear optical responses of LAP in the visible region. In addition, MP2/6-311G results obtained for β(tot) by using isolated and embedded LAP dimers show that crystal packing effects have a significant contribution of the electrostatic interactions. Our results suggest that the role of the crystal environment is to minimize the effects of the intermolecular interactions in the electric properties. That is, μ and β(tot) gain a more additive character in the presence of the field of the embedding charges. This is specially marked for β(tot).

Specific heat measurements in pure and in (Cu, Mn, Fe, Ni)-doped single-crystals of l-arginine phosphate monohydrate

The influence of highly diluted impurities (Cu, Mn, Fe, Ni) on the temperature ( T) dependence of the specific heat ( c p ) of l-arginine phosphate monohydrate (LAP) was investigated in the temperature range 1.8–300 K. The doped samples yielded values for c p in excess to those obtained for a pure LAP sample. The melting temperatures ( T m ≈420 K) obtained by differential scanning calorimetry for pure and doped LAP samples were found not to be significantly affected by the impurities. The T-dependence of c p was fully accounted for by taking into consideration the Debye contribution, an Einstein term and a contribution due to both Frenkel and Schottky defects. The model fit all c p versus T data using a single value for both the Debye ( θ D =160 K) and the Einstein ( T E =376.8 K) temperatures, and for the energy ( ε d =157.9 meV) required to create the defects.

FORMATION OF HOLLOW CAVITIES ON {100} FACES OF LAP CRYSTALS INVESTIGATED BY AFM

Atomic force microscopy (AFM) has been used to study the hollow cavity formation mechanisms of the L-arginine phosphate monohydrate (LAP) crystals. Hollow cavities are formed through three modes. During 2D nucleation growth, initially formed 2D cavity prevents the growth around it layer-by-layer and causes the formation of 3D cavity with stepped-walls inside. Interaction of the steps advancing along different directions generated by different dislocation sources is also responsible for the appearance of hollow cavities. When the steps overrun impurities incorporated into the kinks, triangular pits among regular elementary steps come into being.

Nucleation studies and surface SHG analysis of l-arginine phosphate monohydrate (LAP) family crystals

The metastable zone width and the nucleation parameters, such as interfacial tension, radius of the critical nucleus and critical free energy change have been estimated for pure l-arginine phosphate (LAP), potassium thiocynate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP LAP:Na 2SO 3 single crystals. Pure and additive mixed LAP single crystals are grown by slow cooling technique. The surface second harmonic generation (SHG) analysis is done on (100) face of the grown crystals. The SHG intensity on (100) face of the crystals are measured.

Theoretical studies on vibrational spectra and nonlinear optical property of l-arginine phosphate monohydrate crystal

Linear and nonlinear optical properties of the organic–inorganic hybrid crystal, l-arginine phosphate monohydrate crystal have been investigated by the first-principles calculation as well as the electronic and vibrational properties. The calculated nonlinear optical coefficients agreed well to the experimental data. The results showed both organic and inorganic structural building blocks contribute to the large nonlinear optical activities of this crystal and the significant contribution of the intermolecular hydrogen bonds. The absorption-edges on both IR and UV sides of LAP crystal have been estimated and the structure–property relationship has been discussed. The study is helpful to the further development of l-arginine phosphate monohydrate crystal analogs with improved nonlinear optical properties.