Self-consistent-charge

Frequent approximations made in TB teclmiques in the name of achieving a fast method are the use of a minimal basis set, the lack of a self-consistent charge density, the fitting of matrix elements of the potential. 

Elstner M, Porezag D, Jungnickel G, Eisner J, Flaugk M, Frauenheim Th, Suhai S and Seifert G 1998 Self-consistent-charge density-functional tight-binding method for simulations of complex materials properties Phys. Rev. B 58 7260... 

Once the self-consistent charge density is evaluated for a given choice of nuclear coordinates, the corresponding total energy can be found using eqs. (1)-(7). 

MULTI-SCALE QM/MM METHODS WITH SELF-CONSISTENT-CHARGE DENSITY-FUNCTIONAL-TIGHT-BINDING (SCC-DFTB)... 

Keywords Self-consistent-charge density-functional-tight-binding, Generalized solvent boundary... 

Korchowiec J, Uchimaru T (2000) New energy partitioning scheme based on the self-consistent charge and configuration method for subsystems application to water dimer system. J Chem Phys 112(4) 1623—1633... 

In the last example, a serious handicap is the extreme sensitivity of the calculations to the parameterization of the metal atoms. In a paper concerning the spin states of metal dimer complexes (38) as studied by EHT, heavy manipulation of the original theory was needed. In the field of transition metal coordination compounds self-consistent charge (SCC) calculations (of the type already mentioned for electronegative atoms) are essential to obtain the diagonal elements Hu. 

G. Seifert, Phys. Rev. B, 58, 7260 (1998). Self-consistent-charge Density-Functional Tight-binding Method for Simulations of Complex Materials Properties. 

Fig. 2. Interaction cycle in the self-consistent charge calculation.

Table 4 Iterative self-consistent charge calculation at the MP2 level starting from the Gupta-Gupta [14] charge set with fixed charges on Ba and Y ions.

Influence of Electron Correlation on the Electronic Structure of Superconducting Y-Ceramics Table 6 Self-consistent charge and spin distributions at different electron correlation levels... 

Frauenherm, T.. Seifert, G., Elstner, M., Hajnal, Z., Jungnickel. G.. Porezag. D.. Suhai. S.. and Scholz. R. 2000. A Self-consistent Charge Density-functional Based Tight-binding Method for Predictive Materials Simulations in Physics, Chemistry and Biology , Phys. Stat. Sol. B. 217. 41. 

Kalinowski JA, Lesyng B, Thompson JD, Cramer CJ, Truhlar DG (2004) Class IV Charge Model for the Self-Consistent Charge Density-Functional Tight-Binding Method. J. Phys. Chem A, 108 2545-2549... 

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