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Some systematic errors in mindo/3 calculations

✍ Scribed by Samuel P. McManus; Maurice R. Smith

Publisher
Elsevier Science
Year
1978
Tongue
French
Weight
267 KB
Volume
19
Category
Article
ISSN
0040-4039

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✦ Synopsis

In their detailed description and evaluation of the MINDO/3 method Bingham, Dewar, and Lo' pointed out some types of compounds which gave calculated heats of formation which were poorly correlated with experimental values.

They specifically identified acetylene derivatives, small ring compounds, aromatic compounds, and compact, globular molecules as types for which the error in AHf often exceeded 10 kcal/mol. Dewar and Thie12 developed the MNDO method to overcome the problems inherent in the MIND013 method.

The new approach was shown to give improved accuracy with some problem types but it was claimed that four-membered rings and branched compounds remained as problem cases.

πŸ“œ SIMILAR VOLUMES

Evaluation of MINDO/3 calculated structu
Evaluation of MINDO/3 calculated structures. II. Branching errors in alkanes and cycloalkanes
✍ Samuel P. McManus; Maurice R. Smith; Margaret B. Smith; Steven G. Shafer πŸ“‚ Article πŸ“… 1980 πŸ› John Wiley and Sons 🌐 English βš– 463 KB

## Abstract MINDO/3 calculations have been carried out for a series of branched chain alkanes in order to assess effects of branching on calculated geometries and heats of formation (Ξ”__H__~__f__~). With vicinal branching, MINDO/3 calculates the central Cο£ΏC bond to be too long. Bond angles are also

Systematic errors in DFT calculations of
Systematic errors in DFT calculations of haloalkane heats of formation
✍ C. F. Cloud III; M. Schwartz πŸ“‚ Article πŸ“… 2003 πŸ› John Wiley and Sons 🌐 English βš– 81 KB

## Abstract The B3LYP and B3PW91 density functionals were employed with a large [BS1 = 6‐311+G(3df,2p)] and small [BS2 = 6‐311G(d,p)] basis set to compute enthalpies of formation (at optimized MP2/6‐31G(d) geometries and with scaled HF/6‐31G(d) frequencies) in the following series of haloalkanes: (

Parameter errors in LAOCOON 3 calculatio
Parameter errors in LAOCOON 3 calculations
✍ D. F. Ewing πŸ“‚ Article πŸ“… 1975 πŸ› John Wiley and Sons 🌐 English βš– 468 KB

## Abstract Some model calculations with LAOCOON 3 have been used to show that the mean error in the calculated coupling constants is linearly related to the root mean square error in the transition frequencies. On the basis of this linearity it is shown that the β€˜probable’ error parameter of LAOCO