Recent content by dRic2

Yes it should, because surface contributions scales as ##L^2##, while bulk as ##L^3##, therefore in the thermodynamic limit (##L \rightarrow \infty## they should not matter). That is why I am assuming calculations are not converged. Either that or the software has some problems. from you post I...

Sorry I don't quite follow your tests. First of all, is your system magnetic? About the convergence. Let's start with the SCF. How did you pick 15x15x1? And why those values for the smearing? Also the suggested value for cutoff seems to low in my opinion. Please also converge that value. Note...

I agree that in the limit of thick slab contributions of the surface should impact less, thus, recovering the bulk value. You have a ~15 % relative error, it could be a convergence issue in the DFT. Did you check: - convergence parameters (k-mesh,smearing,cutoff) both for the bulk and slab ? -...

I was talking about Bitcoin. Since 1BTC ~ 60k $, I was wandering how people make transactions valued less than that. I didn't know how BTC is divided and the paper does not discuss this point. From the definition proposed in the paper it does not seem possible to split a coin, thus my confusion.

Ok, after your suggestion I also found this So, to me, it looks like you are simply re-defining the unit of transactions to be 0.00000001 BTC instead of 1 BTC, right? So the whole protocol has to be thought in terms of this smaller unit. Well, yes, but can you handle transactions of less than...

I don't have any special knowledge about cryptography and these kind of technologies. Also my coding skills are pretty basic, so correct me if I understood wrong. I was reading the original paper where the idea of Bitcoin is proposed (ref. https://bitcoin.org/bitcoin.pdf). In Sec. 2...

What is the system you are considering? In general, yes, it should be an integer. You could have non-integer Chern numbers, for example, in a metallic system, because you do not have a gapped band structure at the Fermi level (Chern number non well defined in the conventional sense). But there...

Sorry it was a typo. It should read ##+|b|^2## and it should be correct.

Question: since A is hermitian ##\lambda## are reals, so if ##a## is real, then ##\text{Im}(a\lambda) = 0## and $$ |a|^2 - |b|^2 - (a^2 - b^2) = |b|^2 + b^2 = 0 $$ because ##b## is purely imaginary. Right?

Hi, I have a 2x2 hermitian matrix like: $$ A = \begin{bmatrix} a && b \\ -b && -a \end{bmatrix} $$ (b is imaginary to ensure that it is hermitian). I would like to find an orthogonal transformation M that makes A skew-symmetric: $$ \hat A = \begin{bmatrix} 0 && c \\ -c && 0 \end{bmatrix} $$ Is...

I am rusty, but I try. According to Wikipedia the first-order correction is $$\bra{GS} H_{int} \ket{GS}$$ (assuming you want to calculate the correction to the ground state ##\ket{GS}##). Your ground state is the vacuum for both oscillators so ##\ket{GS} = \ket{0}\ket{0}##. Where ##\ket{0}...

Sorry If I am so late in replying. So, apparently, it's not a great idea to run Macbooks laptops without a battery (https://apple.stackexchange.com/questions/286211/can-macbooks-run-without-a-battery). My System Information says that the battery should be changed but I can also still run my...

Those battery don't not have too nice reviews... but for 60$ I guess they are worth a try. I will not use it much either so... Thanks all for the suggestions!

Thanks for the information. I also googled a bit, but I found people concerned about not being able to use the laptop as a laptop anymore (which is not my case since I want to convert it to a full desktop computer). I didn't know it could get damaged that badly.

I have a 6 years old MacBook air, still running the OS of a couple of years ago. Lately, battery life is going down (around 4.5 hours of light/medium use) so I mainly use it as a desktop computer, connected to an external monitor. However, when I leave it in sleep mode (still on, but shell...