What is CNDO/2?
'''CNDO''' is the short cut for '''Complete Neglect of Differential Overlap'''. It is both 1) a [[wikt:method|method]] for learning key facts about [[molecular orbital]]s as well as 2) the name of a particular set of [[computer program]]s. CNDO is based on [[quantum chemistry]]. It is one of the first [[semi-empirical quantum chemistry methods]]. It uses two [[approximation]]s: *core approximation - only the outer [[valence electron]]s are explicitly included. *[[zero-differential overlap]] CNDO builds a [[mathematical model]] of a [[molecule]]. CNDO starts with the position of the [[positive]]ly charged [[Nucleus (physics)|nuclei]] of the [[atom]]s and the [[negative]]ly charged [[electron cloud]]s surrounding them. Quantum chemistry tells the model the [[probability distribution]] of electron locations based on [[atomic orbital]]s. From this [[information]], CNDO computes [[Information|data]] about the resulting [[molecular orbital]]s. CNDO/2 is the main version of CNDO. [[John Pople]] and coworkers first wrote CNDO/2.<ref>J. Pople and D. Beveridge, ''Approximate Molecular Orbital Theory'', McGraw-Hill, 1970. </ref><ref>J.A. Pople, D.P. Santry and G.A. Segal, Journal of Chemical Physics, '''43''', S129, (1965)</ref><ref>J.A. Pople and G.A. Segal, Journal of Chemical Physics, '''43''', S136, (1965)</ref><ref>J. Pople and G.A. Segal, Journal of Chemical Physics, '''44''', 3289 (1966)</ref><ref>D.P. Santry and G.A. Segal, Journal of Chemical Physics, '''47''', 158 (1967)</ref> ==References== <references/> ==Other websites== *[http://www.pirika.com/chem/MOE/CNDO.htm CNDO/2 Calculation (Pirika)] *[http://www.norgwyn.com/mmequantum.html Molecular Modeling for Educators] {{Webarchive|url=https://web.archive.org/web/20051104002333/http://www.norgwyn.com/mmequantum.html |date=2005-11-04 }} *[http://www.hpc.susx.ac.uk/~ewels/science/thesis/html/node23.html Density Functional Modelling of Point Defects in Semiconductors] {{Webarchive|url=https://web.archive.org/web/20050907151056/http://www.hpc.susx.ac.uk/~ewels/sci