MOLCAS

The MOLCAS program of Professor Bjorn Roos webpage teobor garm.teokem.lu.se A nice compendium of various softwares Is given In the appendix of reviews In ... 

K. Andersson, M, Blomberg, M, Fiilscher, G. Karlstrom, R. Lindh, P.-A, Malmqvist, P. Neogrady, J. Olsen, B, Roos, A, Sadlej, M. Schiitz, L. Seijo, L. Serrano-Andres, P. Siegbahn, and P,-0. Widmark, MOLCA. S, Version 4, Lund University, Sweden, 1997. 

Cl results can vary a little bit from one software program to another for open-shell molecules. This is because of the HF reference state being used. Some programs, such as Gaussian, use a UHF reference state. Other programs, such as MOLPRO and MOLCAS, use a ROHF reference state. The difference in results is generally fairly small and becomes smaller with higher-order calculations. In the limit of a full Cl, there is no difference. 

Molden (we tested Version 3.6) is a molecular display program. It can display molecular geometries read from a number of molecular file formats. Various views of the wave function can be displayed from the output of the Gaussian and GAMESS programs. Some functionality is available from MOP AC and AMP AC files. Conversion programs are available to import wave functions from ADF, MOLPRO, ACES II, MOLCAS, DALTON, Jaguar, and HONDO. 

A. R. Tate, P. J. D. Foxall, E. Holmes, D. Molca, M. Spraul, J. K. Nicholson, J. C. Lindon 2000, (Distinction between normal and renal cell carcinoma kidney cortical biopsy samples using pattern recognition of H-l magic angle spinning (MAS) NMR spectra), NMR Biomed. 13, 64-71. 

Karlstrom G, Lindh R, Malmqvist P-A, Roos B, Ryde U, Veryazov V, Widmark P-O, Cossi M, Schimmelpfennig B, Neogrady P, Seijo L (2003) Molcas a program package for computational chemistry. Comput material sci 28 222... 

Ungur, L. and Chibotaru, L.F. (2006-2013) SINGLE ANISO Program, KU Leuven, Belgium, http //www.molcas.org (accessed 09 September 2014). 

It is not possible to use normal AO basis sets in relativistic calculations The relativistic contraction of the inner shells makes it necessary to design new basis sets to account for this effect. Specially designed basis sets have therefore been constructed using the DKH Flamiltonian. These basis sets are of the atomic natural orbital (ANO) type and are constructed such that semi-core electrons can also be correlated. They have been given the name ANO-RCC (relativistic with core correlation) and cover all atoms of the Periodic Table.36-38 They have been used in most applications presented in this review. ANO-RCC are all-electron basis sets. Deep core orbitals are described by a minimal basis set and are kept frozen in the wave function calculations. The extra cost compared with using effective core potentials (ECPs) is therefore limited. ECPs, however, have been used in some studies, and more details will be given in connection with the specific application. The ANO-RCC basis sets can be downloaded from the home page of the MOLCAS quantum chemistry software (http //www.teokem.lu.se/molcas). 

A wonderful collaboration and friendship with Bjorn O. Roos over the years has certainly been inspiring for the author. All the developers of MOLCAS, whose effort has been essential in order to study such an exciting chemistry, should also be acknowledged, especially Roland Lindh, Per-Ake Malmqvist, Valera Veryazov, and Per-Olof Widmark. The Swiss National Science Foundation, Grant 200021-111645/1, is acknowledged for financial support. 

All calculations were carried out with the software MOLCAS-6.0 [16]. Scalar relativistic effects were included using a DKH Hamiltonian [14,15]. Specially designed basis sets of the atomic natural orbital type were used. These basis sets have been optimized with the scalar DKH Hamiltonian. They were generated using the CASSCF/CASPT2 method. The semi-core electrons (ns, np, n — 3,4, 5) were included in the correlation treatment. More details can be found in Refs. [17-19]. The size of the basis sets is presented in Table 1. All atoms have been computed with basis sets including up to g-type function. For the first row TMs we also studied the effect of adding two h-type functions. 

B. O. Roos, The ANO-RCC basis sets are included in the MOLCAS-6 basis set library. They can be downloaded from the MOLCAS homepage (www.teokem.lu.se/molcas), 2004. 

The computational details concerning basis sets and geometries are given in the following section. The MOs have been calculated with the MOLCAS series of programs [44]. The (SC) -MR-SDCI have been calculated with the CASDI series of programs [41,45] as adapted to run on IBM RS/6000 workstations and on SGI multiprocessor computers. 

MOLCAS version 2, 1991, Andersson K, Fliischer MP, Lindh R, Malmqvist P-A, Olsen J, Roos BO, Sadlej A, University of Lund, Sweden, and Widmark P-O. IBM Sweden... 

Several different versions of second-order perturbation theory for multireference wave functions have been implemented but the one currently in widest use is probably the CASPT2 method. This method was developed by Roos and co-workers in Lund, Sweden, and it is available in their MOLCAS package of computer programs. 

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