Programs Turbomole

Ahlrichs R, Bar M, Ehrig M, HSser M, Horn H, Kolmel Ch (1989) Program TURBOMOLE, Version 2.0 Beta, UniversitSt Karlsruhe (suited for workstations)... 

Ahlrichs R, Bar M, Haser M, Horn H, Kolmel C (1989) Electronic structure calculations on workstation computers The program system turbomole. Chem Phys Lett 162 165-169... 

All quantum chemical calculations were performed with the TURBOMOLE suite of programs. 

All electron calculations were carried out with the DFT program suite Turbomole (152,153). The clusters were treated as open-shell systems in the unrestricted Kohn-Sham framework. For the calculations we used the Becke-Perdew exchange-correlation functional dubbed BP86 (154,155) and the hybrid B3LYP functional (156,157). For BP86 we invoked the resolution-of-the-iden-tity (RI) approximation as implemented in Turbomole. For all atoms included in our models we employed Ahlrichs valence triple-C TZVP basis set with polarization functions on all atoms (158). If not noted otherwise, initial guess orbitals were obtained by extended Hiickel theory. Local spin analyses were performed with our local Turbomole version, where either Lowdin (131) or Mulliken (132) pseudo-projection operators were employed. Broken-symmetry determinants were obtained with our restrained optimization tool (136). Pictures of molecular structures were created with Pymol (159). 

Anyway, the first step toward any receptor-based COSMO-RS calculations is the calculation of qualitatively acceptable er-profiles of the receptor regions of enzymes. In a performance test of a highly parallel version of the TURBOMOLE program on the supercomputer at the Research Center Jiilich [141], we could show that TURBOMOLE presently can handle single point, i.e., fixed geometry, BP-SVP DFT-calculations of enzymes up to about 1,500 atoms. On the basis of preliminary data, an enzyme of 1,000 atoms requires about 6 CPU h on 32 CPUs of a supercomputer cluster with a minimum quadratic scaling of CPU-time with the number of atoms of the enzymes. Thus for medium-sized enzymes we would require a minimum of 600 h on such a supercomputer, which would be rather expensive, even if all the technical problems arising at these molecule sizes would be solved. Therefore, brute-force DFT calculations appear to be unfeasible at present, but they may be possible in the future. 

TURBOMOLE, Program Package for ab initio Electronic Structure Calculations, User s manual, TURBOMOLE Version 5.8, 2005. 

At first sight, it appears that the developers of quantum chemistry (QC) codes, such as Gaussian,SPARTAN,ACES, °i and TURBOMOLE,i°2 made only modest progress in moving to parallel platforms partly because of the size of these programs. Despite an explosion in the number of people using... 

Electronic Structure Calculations on Workstation Computers The Program System TURBOMOLE. 

Electronic Structure Calculations on Workstation Computers the Program System TURBOMOLE, R. Ahlrichs, M. Bar, M. Haser, H. Horn and Ch. Kalmel, Chem. Phys. Letters, 1989, 162, 165... 

However, the BSSE problem is still not entirely solved. As going to larger basis sets is prohibited for large systems, we adopt the modifled DFT-D3(BJ) parameters shown in Table 6.2, which were determined by us according to the procedure by Grimme et al. [16] these calculations were carried out with the Turbomole 6.1 program package [107-109]. 

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