Potential energy curves for Mo2: multi-component symmetry-projected Hartree–Fock and beyond

摘要: The molybdenum dimer is an example of a transition metal system with formal sextuple bond that constitutes challenging case for ab initio quantum chemistry methods. In particular, the complex binding pattern in Mo2 molecule requires high-quality description non-dynamic and dynamic electron correlation order to yield correct shape potential energy curve. present study examines performance recently implemented multi-component symmetry projected Hartree–Fock (HF) approach. this work, spin spatial symmetries trial wavefunction written terms non-orthogonal Slater determinants are deliberately broken then restored variation-after-projection framework. resulting symmetry-projected HF wavefunctions, which possess well-defined numbers, can account static some correlations. A single configuration D∞hS-UHF or D∞hKS-UHF framework offers reasonable curve ...