July 30, 2014
Yan Zhao, Jocelyn M. Rodgers, Benjamin J. Lynch, Núria González-García, Patton L. Fast, Jingzhi Pu, Yao-Yuan Chuang, Benjamin A. Ellingson, Rubén Meana-Pañeda, and Donald G. Truhlar
Department of Chemistry and
multilevel is a computer program written in FORTRAN90 for performing geometry optimizations and calculating single-point energies, gradients, and/or Hessians using two types of dual-level and multi-level methods: integrated molecular orbital (IMO) methods and linear combination (LC) methods. The IMO option is implemented using the integrated molecular orbital method with harmonic cap (IMOHC), and the LC methods include the linear mixing of Hartree-Fock and molecular orbital (HF||MO) method, the scaling all correlation (SAC) method, the Gaussian-x (Gx) methods, the infinite basis (IB) method, and the multi-coefficient (MC) methods, where the MC methods include the multi-coefficient correlation method (MCCM), the multi-coefficient scaling all correlation (MCSAC) methods, the multi-coefficient Gaussian-x (MCGx) methods, the multi-coefficient quadratic configuration interaction with single and double excitations (MC-QCISD) method, and doubly hybrid density functional theory (DHDFT) methods. In the case of DHDFT, the multilevel-v4.4 program can perform calculations by the MC3BB and MC3MPW methods. The program contains several options for optimizing stationary points (minima and saddle points), and it also contains the Nudged Elastic Band (NEB) method, which can be used both to optimize saddle points and to calculate reaction paths. The multilevel-v4.4 program can also use the optimizers in the gaussian program to perform geometry optimization. Note that the use of multileveldoes not require the gaussian program, though; it can be used with the output of any electronic structure package. The code contains 29 test runs.
Publications of results obtained with the MULTILEVEL - version 4.4 software should cite the program and/or the article describing the program.
No guarantee is made that this software is bug-free or suitable for specific applications, and no liability is accepted for any limitations in the mathematical methods and algorithms used within. No consulting or maintenance services are guaranteed or implied.
The use of the MULTILEVEL - version 4.4 implies acceptance of the terms of the licenses. The software may be downloaded here.