Tagged Questions
1
vote
1answer
64 views
Ground state energy of hydrogen molecule ion
In this paper, it is mentioned:
Furthermore, since the
energy of $H_2^+$in the ground state must be lower than that of an
H atom in the ground state,the negative (attractive) forces in the
...
0
votes
0answers
33 views
Implication of Fock matrix elements
In linear combination of atomic orbitals/molecular orbital based quantum chemistry theory, when the block of Fock matrix elements connecting occupied with virtual orbitals is zero, why does this imply ...
2
votes
2answers
134 views
Changes in Water Bonding Angle
I heard something recently in a casual discussion, but have yet to be able to confirm it: is there any evidence that the bonding angle for a water molecule, currently defined as 104.5, has been either ...
2
votes
1answer
270 views
Theoretical treatment of Hydrogen bond?
I would like to understand how the Hydrogen bond can be described through the Schroedinger equation. I don't need numerical methods that one uses them to simulate it, rather I need its treatment from ...
1
vote
1answer
184 views
Minimizing the energy of a Slater determinant: why are the Lagrange multiplier elements of a Hermitian matrix?
If I want to minimize the energy of a Slater determinant subject to the constraint that the spin orbitals are orthonormal (as in the Hartree-Fock approximation), I can use Lagrange's method of ...
3
votes
1answer
105 views
Experiment to find structure of water
Who first determined the structure of water (two hydrogen atoms stuck to an oxygen atom at approx 105 degrees), and, more importantly, how was this done?
3
votes
3answers
356 views
Why is quantum physics needed to explain photosynthesis?
Why is quantum physics needed to explain photosynthesis?
In what aspect does the corresponding classical theories for photosynthesis fail?
2
votes
1answer
2k views
Why is oxygen in a triplet state and what are the consequences?
From Wikipedia here and here:
''Almost all molecules encountered in daily life exist in a singlet state, but molecular oxygen is an exception.''
''The unusual electron configuration prevents ...
6
votes
2answers
449 views
Why does iteratively solving the Hartree-Fock equations result in convergence?
[ Cross-posted to the Computational Science Stack Exchange: http://scicomp.stackexchange.com/questions/1297/why-does-iteratively-solving-the-hartree-fock-equations-result-in-convergence ]
In the ...
2
votes
2answers
735 views
Software to simulate and visualize atoms?
Not sure if this is a physics or chemistry question. But if the motion of atoms and it's particles can be described by quantum mechanics, then is there a software that simulate full atoms and it's ...
