Complete optimisation of multi-configuration Jastrow wave functions by variational transcorrelated method

Abstract

We investigate the performance of the newly developed variational transcorrelated (VTC) method (H. Luo, J. Chem. Phys. 133, 154109 (2010)) on the overall optimisation of the multi-configuration Jastrow wave function. Similar to the standard multi-configuration self consistent field methods, optimisations of orbitals are realized by iterative unitary transformations, where the skew-symmetric matrix elements are determined by using Newton-Raphson scheme. Third order density matrices are introduced to deal with the three-body VTC potential. Test calculations are performed for the C(2) molecule on several small complete active spaces, and the results are compared with those of variational quantum Monte Carlo calculations. The results demonstrate that with the VTC method one can practically recover the results of highly non-linear variational calculations.