DMRG has been used to probe the character of acenes, to perform FCI calculations on diatomics, including Cr2, and a wide array of large inorganic systems. Despite its successes to treat highly-correlated chemical systems, its usage has not expanded beyond the specialized research group. This may principally be due to the wave-function ansatz requiring both a particular set of orbitals, as well as a specific ordering to recover the appropriate correlations. In the present contribution, we provide a set of rules to enable the widespread use of DMRG for finite chemical systems. Specifically, we provide insight on the type and shape of orbitals that are useful in different situations: the size of the auxiliary basis when going beyond 1D systems, the effect of orbital ordering, and the amount of noise needed in order to obtain accurate results using DMRG for chemical systems. We will present these rules based on calculations using 2D-like polyaromatic hydrocarbons and transition metal complexes. The latter includes systems that have complicated spin states that have been to-date difficult to elucidate using both single-reference methods and (small) active spaces.

Useful parameters of DMRG for everyday quantum chemistry applications

246th National Meeting (2013)

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