Sent to CCL by: "Lydia Rhyman" [lyd_rhyman:_:hotmail.co.uk] Dear CCL Users In one of the NBO results, for a P-S bond in a molecule, I got sigma P-S = 0.612 (sp7.68)P + 0.791 (sp7.29)S I cannot understand the meaning of p power 7.68 and p power 7.29. Any help or suitable reference to understand NBO? Many thanks. L. Rhyman