Author Archives: alan
Shift prediction for RI (and ArI and I-anything) molecules is impossible using the 6-31G*basis set because these basis functions have not been defined for iodine. Use 6-311G*.
The computers in C203 are equipped with i7 8-core processors and 8G of total RAM. This occasionally leads to “out of memory” errors. These errors are particularly common during Spartan DFT IR calculations (a typical output error message reads, “Error … finish reading ‘Out of Memory’ Errors in Spartan
Parts of Weinhold’s Natural Population Analysis (NAO, NBO, but not NHO, NRT, perturbation calculations, etc.) have been part of Spartan from the very beginning, but the instructions for accessing this analysis keeps changing. Here is my understanding of what parts … finish reading Spartan tip – Natural Bond Orbitals
Here’s the set up: I draw three chemical structures on the board, all of them unfamiliar. Then I ask you some questions: Which one has the strongest odor? Which one raises your body temperature the most? Which one is most … finish reading Predicting bioactivity of toxic chemicals
Spartan automatically examines models for symmetry. When it finds symmetry elements, it applies these in subsequent calculations. For example, if you build ‘flat’ NH3 (possible point groups: Cs, C3v, D3h, etc.) and calculate its equilibrium geometry, you will end up … finish reading Spartan tip – Symmetry errors
This question is asked in a particularly interesting way by G.E. Höst et al in the December issue of J. Chem. Ed. (“Students’ Use of Three Different Visual Representations to Interpret Whether Molecules are Polar or Nonpolar”, DOI: 10.1021/ed2001895). They … finish reading Can a picture tell you whether a molecule is polar?
This info has been knocking around my email inbox for a long time (rec’d from Wavefunction help on 9/15/2009), but while Spartan has moved on to Spartan’10 (’12 or ’13 just around the corner), maybe the advice is still useful.
My 2011-12 sabbatical is entering its final weeks and I am already receiving emails about college business that supposedly only I can deal with. Sigh. So whatever happened to that long list of possible sabbatical projects I outlined last… Continue reading