Two-electron Reduced Density Matrix Software

Introduction to the 2-RDM

The basic variable of many-electron quantum mechanics is typically chosen to be the N-electron wave function where N is the number of electrons in the quantum system. The N-electron wave function, however, contains much more information than is necessary for the determination of molecular energies and properties. In two-electron reduced density matrix (2-RDM) methods the 2-RDM of an atom or molecule is directly computed rather than the N-electron wave function. The 2-RDM must be contrained by a set of constraints, known as N-representability conditions, to ensure that it corresponds to at least one N-electron density matrix. The family of 2-RDM methods can accurately compute strongly correlated molecules at a polynomial computational scaling.

Software for the 2-RDM

Open-source code from the Mazziotti Group is available on Github. Furthermore, several 2-RDM methods developed by the Mazziotti Group including the variational 2-RDM (v2-RDM), the anti-Hermitian contracted Schrödinger equation (ACSE), the parametric 2-RDM (p2-RDM) methods have been implemented in the Maple Quantum Chemistry Package from RDMChem.