Exponentially and pre-exponentially correlated Gaussians for atomic quantum calculations.

Explicitly correlated, n-electron, one-center s Gaussian (ECG) functions that depend on the interelectron distances in the exponent are combined with s ECGs which also depend on the interelectron separations through pre-exponential r(ij)(2) multipliers. The pre-exponentially r(ij)(2)-dependent ECGs are included in the basis to better describe the interelectron correlation and the interelectron cusps. The basis set is tested in the calculations of the ground state of the beryllium atom ((9)Be).

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