The multireference problem is considered one of the great challenges in coupled‐cluster
(CC) theory. Most recent developments are based on state‐specific approaches, which …

Internally contracted multireference coupled cluster (ic-MRCC) methods with perturbative
treatment of triple excitations are formulated based on Dyall's definition of a zeroth-order …

A unitary wave operator, exp (G), G+=− G, is considered to transform a multiconfigurational
reference wave function Φ to the potentially exact, within basis set limit, wave function Ψ …

This is a companion to: Nonorthogonal orbital based N-body reduced density matrices and
their applications to valence bond theory. II. An efficient algorithm for matrix elements and …

We present the formulation and the implementation of a spin-free state-specific multi-
reference coupled cluster (SSMRCC) theory, realized via the unitary group adapted (UGA) …

Nonorthogonal orbital based N-body reduced density matrices and their applications to valence
bond theory. I. Hamiltonian matrix elements between internally contracted excited valence bond …

Nondynamical electron correlation based on a genuine multiconfigurational theory is of
considerable importance for a balanced ab initio calculation of aromatic and antiaromatic …

Properly spin-adapted coupled-cluster theory for general open-shell configurations remains
an active area of research in electronic structure theory. In this contribution we examine …

A multireference second order perturbation theory based on a complete active space
configuration interaction (CASCI) function or density matrix renormalized group (DMRG) …

Profiling a potential energy surface (PES), all the way to dissociate a molecular state into
particular fragments and to display real or avoided crossings, requires a multireference …