Turbomole computer program

For ab initio calculations of vibrational spectra, a number of computer programs are available CADPAC, Gamess, Gaussian, HyperChem, Q-Chem, Spartan, and Turbomole, to name only the most well known. Most of them are sold commercially, and free ones are also available and, fortunately, these have comparable performance. 

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... 

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... 

Erisch MJ et al (2009) GAUSSIAN 09 (Revision A.02). Gaussian Inc, Wallingford 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 Ditto M, Brunner H, Lippitsch ME (1991) Picosecond spectroscopy of dihydro bdiverdin. Chem Phys Lett 185 61-64... 

R. Ahlrichs, M. Bar, M. Haser, H. Horn, C. Koknel, Electronic structure calculations on workstation computers The program system Turbomole, Chem. Phys. Lett. 162 (1989) 165 M. Haser, R. Ahlrichs, Improvements on the direct SCF method, J. Comput. Chem. 10 (1989) 104 O. Treutler, R. Ahlrichs, J. Chem. Phys. 102 (1995) 346 R. Bauernschmitt, R. Ahlrichs, Treatment of Electronic Excitations within the Adiabatic Approximation of Time Dependent Density Functional Theory, Chem. Phys. Lett. 256 (1996) 454 S. Grimme, F. Furche, R. Ahlrichs, An improved method for density functional calculations of the frequency-dependent optical rotation, Chem. Phys. Lett. 361 (2002) 321 F. Furche,... 

The stnictures of the isomeric zwitterions 6a and 6b and five different structures of the anion 7 were studied by quantum-chemical methods. For this purpose, geometry optimizations at the SCF level with an optimized SVP basis set [23] were performed using the TURBOMOLE program system [24], Generally, the results of the computational studies were in good agreement with the experimentally established data. 

The CCSD(F12) model as well as the full CCSD-F12 approach and other simplifications of it are currently being implemented in various quantum chemistry programs [59, 61, 62, 71, 72, 73, 74, 75, 76, 77, 78, 79], also in combination with connected triples and higher excitations. In particular Kohn and co-workers [72] have shown that the CCSD(F12) model is an excellent approximation to the full CCSD-F12 approach, and the CCSD(F12) model is the method of choice that we have implemented in the Turbomole program. The present work reports on one of the first applications of CCSD(F12) theory" with chemical relevance. In such a real-life application, CCSD(F12) calculations are combined with a series of other coupled-cluster calculations including geometry optimizations, calculations of harmonic vibrational frequencies, and coupled-cluster calculations with connected triples and quadruples. Within the whole set of calculations that must be performed, the CCSD(F12) calculations take only a fraction of the total computation time, and therefore, in an application as the one presented here, there appears to be no need to further simplify the CCSD(F12) model. 

All explicitly correlated calculations were performed at the CCSD(F12) level of theory, as implemented in the TurbomOLE program [58, 69]. The Slater-type correlation factor was used with the exponent 7 = 1.0 aQ. It was approximated by a linear combination of six Gaussian functions with linear and nonlinear coefficients taken from Ref. [44]. The CCSD(F12) electronic energies were computed in an all-electron calculation with the d-aug-cc-pwCV5Z basis set [97]. For all cases we used full CCSD(F12) model (see Subsection 4.9 for the discussion about models implemented in Turbomole), the open-shell species were computed with a UHF reference wave function. The explicitly correlated contributions to the relative quantities are collected in Tables 10 and 11 under the label F12 . 

Horn, H., and Koelmel, C. (1989) Electronic stmcture calculations on workstation computers the program system TURBOMOLE. Chem. Phys. Lett., 162 (3), 165-169. 

Turbomole (www.cosmologic.de/QuantumChemistry/main qChemistry.html) is an ab initio and density functional program that runs on workstations and Windows and Macintosh computers. 

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