The MRCC program system: Accurate quantum chemistry from water to proteins

Abstract

MRCC is a package of ab initio and density functional quantum chemistry programs for accurate electronic structure calculations. The suite has efficient implementations of both low- and high-level correlation methods, such as second-order Møller–Plesset (MP2), random-phase approximation (RPA), second-order algebraic-diagrammatic construction [ADC(2)], coupled-cluster (CC), configuration interaction (CI), and related techniques. It has a state-of-the-art CC singles and doubles with perturbative triples [CCSD(T)] code, and its specialties, the arbitrary-order iterative and perturbative CC methods developed by automated programming tools, enable achieving convergence with regard to the level of correlation. The package also offers a collection of multi-reference CC and CI approaches. Efficient implementations of density functional theory (DFT) and more advanced combined DFT-wave function approaches are also available. Its other special features, the highly competitive linear-scaling local correlation schemes, allow for MP2, RPA, ADC(2), CCSD(T), and higher-order CC calculations for extended systems. Local correlation calculations can be considerably accelerated by multi-level approximations and DFT-embedding techniques, and an interface to molecular dynamics software is provided for quantum mechanics/molecular mechanics calculations. All components of MRCC support shared-memory parallelism, and multi-node parallelization is also available for various methods. For academic purposes, the package is available free of charge.

Magnetic moment of Pb207 and the hyperfine splitting of Pb81+207

“…The largest used QZQZ basis set corresponds to the uncontracted Dyall's AAE4Z basis set on Pb and Dyall's ACV4Z on F [27,28]. The QZDZC basis set corresponds to the uncontracted AAE4Z basis set on Pb and contracted aug-cc-pVDZ [29,30] on F. In the TZDZC basis set the uncontracted AAE3Z [27,28] basis set is used for Pb and contracted aug-cc-pVDZ [29,30] for F. Finally, we also used the DZDZC basis set which corresponds to uncontracted CVDZ [27,28] basis set on Pb and contracted aug-cc-pVDZ [29,30] on F. Relativistic four-component calculations were performed within the locally modified DIRAC15 [24] and MRCC [31] codes. For calculation of the hyperfine-interaction and g-factor matrix elements the code developed in Refs.…”

Effect of NH3 and HCOOH on the H2O2 + HO → HO2 + H2O reaction in the troposphere: competition between the one-step and stepwise mechanisms

“…The scaling factor employed to adjust the ZPEs was 0.9490. 46 The reliability of CCSD(T)-F12a/cc-pVDZ-F12 method was further tested by the single point energies of H 2 O 2 + HO / HO 2 + H 2 O reaction at the W3X-L and W2X 47 using MRCC 48,49 program packages. It is noted that quantitative barrier heights 47,[50][51][52][53] for complex atmospheric reactions can be obtained using W3X-L, where the accuracy of W2X and W3X-L can respectively reach for the all-electron scalar-relativistic CCSD(T)/ CBS and CCSD(Q)/CBS.…”

Novel strategy to implement active-space coupled-cluster methods

“…The calculations were performed using the new program and the previous SRMRCC code which is the part of the Mrcc program package. 49 The comparison of the measured timings can be found in Table I. The calculations were performed on a single thread of a 3.5 GHz Intel Xeon E5-1650 processor with 125 Gbyte memory.…”