Modified Gaussian functions and their use in quantum chemistry. I. Integrals

Abstract A modified Gaussian function g ( u , v , w , a , R ) = const equation image s ( a , R ) is considered where l = u + v + w , s ( a , R ) is a 1 s ‐type Gaussian function centered at R , a is the coefficient in the exponent of the 1 s Gaussian function and X , Y , Z are components of R . General formulae are derived for overlap integrals, kinetic energy integrals, nuclear attraction integrals, and electron repulsion integrals, valid for any l . The formulae are much simpler than those derived by Huzinaga for Cartesian Gaussian functions.