Basis Set

Basis (universal Algebra) - Definitions
... The basis (or reference frame) of a (universal) algebra is a function b that takes some algebra elements as values and satisfies either one of the following two equivalent conditions ... Here, the set of all is called basis set, whereas several authors call it the "basis" ... The set of its arguments i is called dimension set ...

Roothaan Equations
... equations are a representation of the Hartree-Fock equation in a non orthonormal basis set which can be of Gaussian-type or Slater-type ... coefficients, S is the overlap matrix of the basis functions, and is the (diagonal, by convention) matrix of orbital energies ... In the case of an orthonormalised basis set the overlap matrix, S, reduces to the identity matrix ...

Basis Set (chemistry) - Split-valence Basis Sets - Pople Basis Sets
... The notation for the split-valence basis sets arising from the group of John Pople is typically X-YZg ... case, X represents the number of primitive Gaussians comprising each core atomic orbital basis function ... The Y and Z indicate that the valence orbitals are composed of two basis functions each, the first one composed of a linear combination of Y primitive Gaussian functions, the other composed of a ...

Full Configuration Interaction - Explanation
... of the electronic molecular Hamiltonian within the basis set of the above mentioned configuration state functions ... In a minimal basis set a full CI computation is very easy ... But in larger basis sets this is usually just a limiting case which is not often attained ...