energy of water is the energy of the dimer minus two times the energy of a single water
molecule (E
dimer
– 2*E
water-alone
). Now do the same thing with 3 water molecules. Now the
binding energy will be E
trimer
– 3*E
water-alone
. Run these calculations using B3LYP/Routine
and HF/Routine. How do O---H distances compare and binding energies compare between
the two methods?
5.
The experimental bond length of CO
2
is 1.162 Å and CO
2
has an atomization energy (CO
2
à
C + 2O) of 381.9 kcal/mol. Note that O is a triplet in ground state and C is a triplet also
(Multiplicity 3). Compare the accuracy of different exchange-correlation functionals. Use
a 6-31G(d) basis set (Routine) and the following exchange-correlation functionals: HF,
LDA, PBE, BLYP, B3LYP, and m05-2x. Each of these methods represents a different class
of functionals. Run these jobs as “Geometry Optimization” calculations.
You’ll need to specify the exchange correlation methods in Webmo. To do this at the job
menu click “Preview”. Then click “Generate”. This will show you the job input file. The

#### You've reached the end of your free preview.

Want to read all 3 pages?