Recent content by jpr0

If you're comparing the results of a DFT calculation to a phenomenological nearest-neighbour tight-binding Hamiltonian then you should find that in the tight-binding band structure the conduction and valence bands are symmetric about the Dirac point (about the line E=0). From a DFT...

0,0,0,0,1,0,0,1 is perfectly valid. This would correspond to sampling 2 families, the first one of which had 4 girls and one boy, and the second of which had 2 girls and 1 boy. Edit: I wasn't thinking of how to calculate this computationally, which is a fairly easy task. I'm just trying to cut...

I think you can formulate an equivalent problem in the following way: You're given a binary string, x, of length N bits. Each bit in the string is chosen randomly from {0,1}, except the last bit of the string, whose value is always 1. Let z be the number of zeros occurring in x. What is the...

Well, that demonstrates that the ground-state for the 1D Schroedinger equation in a piece-wise constant potential contains no nodes. If that's the OP's question then you can simply solve the SE and verify that the ground state indeed contains no nodes. If you want to prove that it's true in...

Hi, I know this is an old thread, but I have a simple Hamiltonian whose ground state is anti-symmetric. H=\left[\begin{array}{cc}0 & \Delta\\\Delta & 0\end{array}\right]\,. Eigenstates and eigenenergies are: \psi_{\eta}=\left[\begin{array}{c}1\\...

scanf("%d",&p);

By the way to output matrices to file... outfile = fopen(int2str(i),'w'); dummy = fwrite(outfile,M,'float64'); fclose(outfile); This saves the matrix M as binary data to the file 'i'

you need to use the function int2str mystr = int2str(i); alternatively if you want to make the file name "NAMEFILE-i" then you can use sprintf(mystr,'NAMEFILE-%i',i); you'll have to check the syntax of this though, i can't remember it exactly off-hand. note that %i in the second argument...

Noooo Macs are the dark side... They should be banned :P

When I say "pressure" I'm talking about the tangential force extered on the pipe by the fluid divided by the surface area of the pipe. If I take an open pipe through which water is pumped, and then a closed pipe where the pressure is turned down until the pressure is equal to that of the first...

Look at this way: you have 2 pipes, one open ended, one is closed. You're telling me that in the open ended pipe where there is a flow I can have exactly the same pressure as in the first pipe - despite the fact that the fluid is flowing (and that this in some way show's how a microscopic...

Yes they can. If you have 2 identical pipes with 2 identical pressures, one with a moving fluid, while the other holds the same (but stationary) fluid, what can you say about the temperature of the fluids in each of the pipes? What does this tell you about the average velocity of a molecule in...

Maybe it was too cold to begin with :P

First of all choose "download MikTex". As far as I understand it, MikTex is just a windows port of latex. You're probably best off just downloading the basic package - you can later on set MikTex to download packages when it needs them. After it's downloaded, rerun the installer, then choose...

Well, I wasn't checking your algorithm for *what it's supposed to do*, but rather for getting rid of errors due to miscalled functions. Just try outputting values at each point of your algorithm and compare the answer with what you expect you should get. So, take a small number of people, small...