kkrsusc/perform.md

@@ -9,6 +9,7 @@ title: KKRSusc Quickstart Guide
 
 
 
+
 # Perform a KKRsusc calculation
 
 In order to investigate spin-excitations via the KKRsusc program please
@@ -74,7 +75,7 @@ and step 5 is finally performed with the KKRsusc program itself.
 
 ## Step 5: Calculate Self-energy and renormalized spectrum
 
-To calculate the self-energy and renormalised spectrum of the system, a fitting procedure of the Green function to Padé polynomials is used, to facilitate the computational effort necessary to complete the calculation. For that, a set of `kkrflex_*` files similar to step 2 is needed, that contain the information for the host Green function over a large range of energies.
+To calculate the self-energy and renormalised spectrum of the system, a fitting procedure of the Green function to Padé polynomials is used, to facilitate the computational effort necessary to complete the calculation. For that, a set of `kkrflex_*` files similar to step 2 is needed, that contain the information for the host Green function over a large range of energies. The self-energy needs also the `meshpanel.dat` file to work. 
  - Use the file [emesh.dat](emesh.dat), that describes an energy contour from $-0.3$ to $1.3$ Ry to run one iteration using the host code with the run flag `KKRSUSC` like in step 2.
  - Similarly to the susceptibility calculation in step 4, two runs of the code are needed.
  - Set `lfit= T` to instruct the code to run the fitting procedure and set the numerator polynomial degree `numd` and denominator degree `dend` to proper values, with $dend=numd +1$, to match the $1/\omega$ behaviour of the susceptibility in high frequencies. A typical range for `numd` is between 10-30, with the best fits usually in the region of 17-21.