Symmetry-adapted formulation of the G-particle-hole hypervirial equation method

GUSTAVO E. MASSACCESI; DIEGO R. ALCOBA; OFELIA B. OÑA

JOURNAL OF MATHEMATICAL CHEMISTRY

SPRINGER

Lugar: Berlin; Año: 2012 vol. 50 p. 2155 - 2167

0259-9791

Highly accurate 2-body reduced density matrices of atoms and molecules have been directly determined without calculation of their wave functions with the use of the G-particle-hole hypervirial (GHV) equation method (Alcoba et al. in Int. J. Quantum Chem. 109:3178, 2009). Very recently, the computational efficiency of the GHV method has been significantly enhanced through the use of sum factorization and matrix-matrix multiplication (Alcoba et al. in Int. J. Quantum Chem 111:937, 2011). In this paper, a detailed analysis of the matrix contractions involved in GHV calculations is carried out. The analysis leads to a convenient strategy for exploiting point group symmetry, by which the computational efficiency of the GHV method is further improved. Implementation of the symmetry-adapted formulation of the method.