[gmx-users] use of surface tension

[paul buscemi]

Dear users,

I have set up a lipid membrane with its normal in the z direction.  I would like to apply a surface tension only in the x ( or y) direction with the normal pressure at 1atm.  that is - stretch the membrane in one direction

I’ve modified  npt mdp equilibrium file  and have worked with how to apply a xy surface tension using: ( which seems similar to semi-isotropic ) 

pcoupletype 	 =    surface tension

but this is not the objective. 

 Using anisotropic  is the proper setup as follows ?

pcoupletype 	 =    surface anisotropic   ;    from the guide —  6 values are needed for xx, yy, zz, xy/yx, xz/zx and yz/zy components <>
vectors
ref-p 		=       -1        1      1      1      1        1                     ;    apply 1 atm to x direction
compressibility =      1e-4   5e-5   <>5e-5  <>5e-5   <>5e-5   <>5e-5   <>

 <>

 <>
This appears to work,   but is the format correct ?  
Regards
Paul