Voigt function to the 540 cm peak. It is very close to the expected value = 0.34 for a two-body Fe-NO oscillator. The calculated value = 0.39 (B3LYP functional) is in agreement with the experimental one. [Pg.194]

B3LYP (Becke 3 tenn, Lee Yang, Parr), 44, 360. See also Density functional theory [Pg.371]

B3LYP Becke-style 3-Parameter Density Functional Theory Through 2nd derivatives (using the Lee-Yang-Parr correlation functional) [Pg.9]

We win run this job on methane at the Hartree-Fock level using the 6-31G(d) basis our molecule specification is the result of a geometry optimization using the B3LYP Density Functional Theory method with the same basis set. This combination is cited [Pg.21]

Molecular frequencies depend on the second derivative of the energy with respect to the nuclear positions. Analytic second derivatives are available for the Hartree-Fock (HF keyword). Density Functional Theory (primarily the B3LYP keyword in this book), second-order Moller-Plesset (MP2 keyword) and CASSCF (CASSCF keyword) theoretical procedures. Numeric second derivatives—which are much more time consuming—are available for other methods. [Pg.61]

Perform a low-level geometry optimization with a medium-sized basis set, for example, a Hartree-Fock or B3LYP Density Functional Theory calculation with the 6-31G(d) basis set. (For very large systems, a smaller basis set might be necessary.) [Pg.93]

Only the values computed by the hybrid functionals and MP2 are at all reasonable, and the B3PW91 value is in excellent agreement with experimental observations. Thi MP2 and B3LYP values are only modestly outside of the desired accuracy of 2 kcal-mol In Chapter 7, we will consider methods which were developed to consistently produce such very accurate thermochemical results. [Pg.120]

Seluflon Clearly, a hybrid functional is the best choice for this problem. We ran B3LYP calculations using the 6-31G(d), 6-31-i-G(d) and 6-311G(2d) basis sets. Here are the results [Pg.128]

For the Cs and K substituents, all three DFT functionals produce similar structures. All three functionals predict frequencies which are somewhat lower than the observed values but which reproduce the trends in the experimental data quite well. The SVWN5 frequencies tend to be higher than those computed by BLYP and B3LYP. [Pg.135]

Hydroxyfurazans exist solely in the hydroxy form. This is in accord with quantum chemical calculations (Scheme 167). Density functional theoretical studies (B3LYP/6-311- -G(2d,p)) indicate that 3-hydroxyfurazan is more stable than the [Pg.149]

The basis set is 6-31G(d,p), and electron correlation at the MP2 level is included. A similar structure is obtained with the AMI and PM3 semi-empirical methods. Density functional theory at the B3LYP/6-31G(dp,p) level also produced the same structure for this ion-pair. The only observed differences between the semi-empiri-cal and the ab initio structures were slightly shorter hydrogen bonds (PM3 and AMI) between FI, F2, and F5 and the G2-F1 (H18) on the imidazolium ring. [Pg.154]

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