MIDI!

MIDI! (or MIDIX) is a small basis set designed to provide good geometries and partial charges, with emphasis of biomolecules functional groups. Includes d polarization functions for atoms excepting H and C. It is a modification of the original MIDI of Huzinaga. It provides better geometries than the much bigger 6-31G*. MIDIY is an extension that includes p polarization on H. Also MIDIX+ and MIDIY+ were developed

Contractions:

H    :  (3s)       -&gt; [2s] C    :  (6s,3p)    -&gt; [3s,2p] N - F : (6s,3p,1d) -&gt; [3s,2p,1d] P - Cl: (9s,6p,1d) -&gt; [4s,3p,1d] Si   :  (9s,6p,1d) -&gt; [4s,3p,1d] Br   : (15s,9p,4d) -&gt; [5s,4p,2d] I    : (18s,12p,7d) -&gt;[6s,5p,3d]