What is a contracted basis set?

What is a contracted basis set?

Many electronic structure programs use contracted basis sets where the atomic orbitals are made up of a linear combination of primitive STOs or GTOs.

What does double-zeta mean?

Double-zeta basis sets are often denoted DZ. Often additional flexibility is built in by adding higher-angular momentum basis functions. Since the highest angular momentum orbital for carbon is a p orbital, the “polarization” of the atom can be described by adding a set of d functions.

What is a common name for basis set?

The most common minimal basis set is STO-nG, where n is an integer. The STO-nG basis sets are derived from a minimal Slater-type orbital basis set, with n representing the number of Gaussian primitive functions used to represent each Slater-type orbital.

What is 3-21G basis set?

3-21G – (pronounced “three two one jee”) The valence functions are split into one basis function with two GTOs, and one with only one GTO. (This is the “two one” part of the nomenclature.) The core consists of three primitive GTOs contracted into one basis function, as in the STO-3G basis set.

What is the meaning of basis set?

A basis set in theoretical and computational chemistry is a set of functions (called basis functions) that is used to represent the electronic wave function in the Hartree–Fock method or density-functional theory in order to turn the partial differential equations of the model into algebraic equations suitable for …

What is B3LYP?

B3LYP (Becke-3 Parameter-Lee-Yang-Parr), is a very common exchange-correlation functional used in Kohn-Sham density functional theory. It is composed of a linear combination other exchange/correlation functions, that is why is called a hybrid funcitonal.

What is triple zeta basis set?

Basis sets in which there are multiple basis functions corresponding to each valence atomic orbital are called valence double, triple, quadruple-zeta, and so on, basis sets (zeta, ζ, was commonly used to represent the exponent of an STO basis function).

What is a double zeta basis set?

Double-zeta basis Sets The function with the large zeta accounts for charge near the nucleus, while the function with the smaller zeta accounts for the charge distribution at larger values of the distance from the nucleus. This expanded basis set is called a double-zeta basis set.