[FLASH-USERS] Best practice for referencing Abar, Zbar

[Aaron Froese]

Hi all,

A method for calling the local ion mass and charge averaged over all species is listed in the manual.

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#include "Flash.h"
#include "Multispecies.h"
USE Multispecies_interface, ONLY: Multispecies_getSumInv, Multispecies_getSumFrac

call Multispecies_getSumInv(A,abar_inv)
abar = 1.e0 / abar_inv
call Multispecies_getSumFrac(Z,zbar)
zbar = abar * zbar
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However, hy_uhd_getFaceFlux.F90 contains the following code which does not include the Multispecies header file.

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#ifdef YE_MSCALAR
              eosData(EOS_ABAR)=1./U(SUMY_MSCALAR,i-1,j,k)
              eosData(EOS_ZBAR)=U(YE_MSCALAR,i-1,j,k)/U(SUMY_MSCALAR,i-1,j,k)
#endif
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It obviously relies on the ion and electron densities per unit mass SUMY and YE being included as mass scalars in the Config file.

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MASS_SCALAR YE    EOSMAPIN: YE
MASS_SCALAR SUMY  EOSMAPIN: SUMY
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However, when I run a test with one specie of A=1 and Z=1, the latter code gives me Abar=Inf and Zbar=NaN.  Does using mass scalars confer any advantage over using the Multispecies subroutines?  If so, does anyone have an MHD example where the mass scalar approach is working properly?

Thanks,
Aaron