Recent content by Modey3

Because in ordered to be considered BCC every atom (basis set) needs to be the same. Sure CsCl looks like it's BCC, but it doesn't have the same symmetry as pure BCC Cs. BCC is an indicator of symmetry not shape. modey3

The original question was if a wave function for a phonon could be deduced, which could describe it in a way analogous to the electronic wave function. Since a phonon isn't a particle in the same manner as an electron its location cannot be described using a wave function. The paper by S.C...

Hello, Hamamatsu has a nice picture of a photomultiplier: http://learn.hamamatsu.com/articles/photomultipliers.html I've actually never worked with a dynode, but I am wondering if they work by secondary-electron emission and sequent multiplication? Also, how many volts are usually...

To your first question. Not every oscillator will have the same energy. For a given temperature you will have a distribution of harmonic oscillator energies. To your second question. A phonon is a quasi-particle just like a hole, but it isn't a "real" particle like an electron. So it would be...

A phonon is localized to the lattice in which it causes vibrations. When each atom is considered a harmonic oscillator this means they vibrate independently. In essence, the phonon is localized on the atom, however in real crystals atoms don't vibrate independently, and hence a phonon will exist...

When analyzing the chemical composition or structure of a sample the absolute intensities are meaningless and only relative intensities are meaningful. For a given sample, absolute intensities will vary from experiment to experiment, but relative intensities won't. Yes and Yes. For a given...

quietrain, You will need to use more than just one diffraction ring to determine the inter-atomic distance. That's why you need to determine the structure-factor. modey3

quietrain, Graphite is pretty simple when it comes to determining the structure-factor. I won't solve the problem for you, but try to represent graphite in terms of a orthorhombic unit-cell with a multi-atom basis. Find the structure-factor based on that symmetry. There is no easy "plug and...

As a person who holds a BS in Chemical Engineering, there aren't that many differences. A chemical engineer is concerned with designing a reactor, heat exchanger, or any other equipment which deals with chemicals. To do this you need a background in mass transport, reaction kinetics, process...

N8, The highest occupied level (k_max) of a band-diagram corresponds to a point on the Fermi Surface. You could make a band diagram along any direction in the Brillouin Zone and the number of directions is infinite. So you could create a fermi surface if you determined k_max in all...

Folks, This subject is being over-analyzed. IMO the Hall Effect experiment doesn't adequately describe what a hole is. A hole is not a particle. Yes, I said it! A hole is an absence of a particle. In semiconductors the absence of an electron within (not at the top) the DOS is manifested...

Consider a string of hydrogen atoms. If you take away one electron on a particular hydrogen atom you would get a string of something like: ... H, H, H+, H, H ... If the current moves in the right-direction the positive-charge (not the hydrogen cation!) moves in the left-direction. As you can...

The underlying question is this: Should we hold China to the same western standards that we follow? If we do, then yes, the Chinese government is barbaric towards its people. After all, it is against western-standards to execute tax-cheats and I believe the list of crimes that will get you...

ramb, everybody is different. I usually use a couple of books on the same subject: one for priamry reading and the others for clarification. It turns out that actually doing every problem at the end of chapter isn't necessary if you have intimate knowledge of the subject. What I have done in...

So what you are saying is that research groups need to be large so that everyone contributes their narrow-band of skills, which will make that group productive. Do you think that it is necessary for students to be able to repair and modify their own equipment because obviously these skills will...