Larson's Inter-Atomic Distance Calculations

jdalton4 · Post by **jdalton4** » Wed Sep 23, 2015 7:46 pm

I am checking Larson's inter-atomic distance calculations and getting different numbers than the ones he has published. For example, Larson's inter-atomic distrance for table salt is 2.77 Angstroms (Basic Properties of Matter, page 26). My calculations show 2.82. I am using the LN function in EXCEL to do these calculations which have more significant digits than Larson may have used. But I am sure Larson would have had an excellent calculator to do his work. So this difference is still a mystery too me.

bperet · Post by **bperet** » Thu Sep 24, 2015 7:51 am

But I am sure Larson would have had an excellent calculator to do his work. So this difference is still a mystery too me.

Larson did his calculations back in the 1960s, before electronic calculators were invented (mid-1970s.; got my first 4-banger around 1974 in High School Didn't have an LN button until I was in college, and that HP-67 cost $850 back then!)

Larson used a slide rule to do the math, so at best, he has 3 significant digits.

It may also be a printing error. I found quite a few of them in BPOM (particularly Table 35).

If the other numbers are coming out correct, send me your spreadsheet of the table and I'll fix the online PDF.