Quantum chemistry Definition and 74 Threads

1. Consider a particle of mass m in a cubic (3-dimensional) box with V(x,y,z) = 0 for 0 < x < L, 0 < y < L, and 0 < z < L and V(x,y,z) = ∞elsewhere. Is 1/\sqrt{2} * (ψ(1,1,5)+ψ(3,3,3)) an eigenfunction of the Hamiltonian for this system? If so, what is the eigenvalue? Explain your reasoning 2...

'Relativistic Quantum Chemistry' -- Say whut? So I just found out that one of my co-workers (well, someone who works in the same building with me but not directly with me) has a PhD in this field, he took like the last two weeks off for Christmas vacation, but when he explained to me some of...

So I am a chemistry major, but really like math and physics as well. I was wondering how necessary it would be to take quantum physics after taking two semesters of physical chemistry. I go to a small school and there aren't a host of physics classes, so quantum physics is the end of its road...

Homework Statement For a 3-D, spherically symmetric, isotropic harmonic oscillator, use a trial function e^αr^2 as a variational parameter. The Hamiltonian as given by the book is attached, as are two files showing screenshots of my attempt at the solution in Mathcad. I've tried it two...

Author: Attila Szabo, Neil Ostlund Title: Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory Amazon Link: https://www.amazon.com/dp/0486691861/?tag=pfamazon01-20

Author: Donald McQuarrie Title: Quantum Chemistry Amazon Link: https://www.amazon.com/dp/1891389505/?tag=pfamazon01-20

I'm a chemical engineering major and I have to take one of these. Is QM more theory heavy or are they about the same in that regard? I am leaning more towards QM. my only exposure so far has been with the "modern physics" part of general physics

function: e^-(x^2/2) operator: d^2/dx^2 -x^2 The answer key says the function is an eigenfunction of the operator with an eigenvalue of -6. I can't figure out how to reach this conclusion. Also, Wolfram Alpha says d/dx(d/(dx)e^(-x^2/2)) = e^(-x^2/2) (x^2-1). Isn't this inconsistent with...

I was wondering if I do an IRC calculation and the energy range of the IRC does not quite reach the energy of the reactant or product of the system, do I need to make the IRC calculation "wider" (i.e. go more forward and reverse) so that I can interpolate the reaction coordinate of the system...

Hi. I am a 3rd year chemistry student and I want to go into quantum chemistry. What bothers me is that when I talk to all the chemistry students in my class their maths and physics is pretty much on 1st year lvl, because of that the physical chemistry courses seem really weak and I feel that if...

Anyone here know about dickson dips in spectroscopy?

Homework Statement "Use definition (3.219) for the STO-1G function and the scaling relation (3.224) to show that the STO-1G overlap for an orbital exponent zeta = 1.24 at R = 1.4 a. u., corresponding to result (3.229), is S12 = 0.6648. Use the formula in Appendix A for overlap integrals. Do...

I posted this elsewhere but I wasn't sure if physics people were lurking on the chem forum. I want to understand MO and LCAO. The chapters in Levine weren't enough. Are there other books on bonding that people know of?

Homework Statement If we were to ignore the interelectronic repulsion in helium, what would be it's ground state energy and wave function? Homework Equations I have created my ground state wave function \psi for 1s: \psi = (1/\sqrt{}\pi)(z/a)3/2(e-zr/a) The operator is the...

What's the different between quantum chemistry and quantum physics? I did quantum chemistry as elective in second year but I didn't like it. I didn't like the chemistry as a whole though because it's too hard(thousands of reactions that you have to remember in each branch!). I want to switch...

Hi everyone. Im reading quantum chemistry due to an exam, but there are a few things, that I am not sure of: 1. I'm not sure, but as far as i understand, there is coupling between spin and orbital angular momentum, but if L = 0, in an S-orbital: is there then any coupling ? 2. Does...

I'm really struggling on even getting started on this problem. I have read the chapter several times now and I have tried to understand the explanations in the chapter. But I can't even get this problem started. All I ask is if anyone knows how to do this, can you just get me started or point...

I'm really struggling on even getting started on this problem. I have read the chapter several times now and I have tried to understand the explanations in the chapter. But I can't even get this problem started. All I ask is if anyone knows how to do this, can you just get me started or point...

Chemical bonds and quantum entanglement I have a very basic understanding of quantum mechanics and chemistry, so please bear with any misunderstandings I may have. My question is this: what does QM have to do with the bonding between atoms in a molecule or compound? Can these bonds be labelled...

Quantum Chemistry is a real field that interests me (senior in high school). I was wondering what degree i should pursue to get something tha tworks with that. (Molecular Orbitals, etc). Should I do Physics Major and Chemistry minor, or Chemistry Major Physics Minor? Any bit of math involved...

I was wondering if someone could tell me what exactly is the difference between Quantum Chemistry and Quantum Physics? Whenever I look in a Chemistry textbook, I see Quantum Chemistry and the latter is true for Physics - yet strangely enough I see most of the information is quite similar...

Hello, I'm usually a PF user in General Physics/Chemistry, but I might need the help of you quantum physics users :), recently I have started a quantum chemistry module and I'd appreciate if I could clear some stuff up with you guys rather than look like a penis by asking all my friends, who...

There is an initial state Psi(x) =Ax(b/2 - x) when 0< x <b/2 and Psi(x) = 0 when b/2 < x <b I have to find the second lowest value possibly be obtained in a measurement of the energy. Should I treat this as a box with width b and possible energy states E=n^2*h^2/8mb^2 ? Or should I use...

I think it would be great having a thread devoted to Quantum Chemistry. Is anyone interested in learning Quantum Chemistry?