NO Transition state!!!
Posted: Thu Feb 09, 2012 5:02 am
Hi
I am trying to find the transition state for water adsorption on a mineral surface using VASP. I have optimized the adsorption geometry and final geometry (surface and water molecule around 5 angstrom far apart). While I would like to try C-NEB, I have started with NEB. Using 5 images, I got the convergence. But there is no saddle point, rather energy is continuously increasing from adsorption geometry to final geometry through 5 images. I have created the images using the vtst tools. Could anyone please enlighten me on whether I am making any mistake. My INCAR file is:
# ISTART = 0 # 0=start from scratch, 1=use WAVECAR-file (default: 1 if file exists, 0 otherwise)
ENCUT = 400
NSW = 120
EDIFFG = -0.05
IBRION = 1 # ionic relaxation routine -1:no 0:MD 1:Newton(fast) 2:conj.gradient(safest)
ISIF = 2 # relax ions only
ISMEAR = 0 # 0=Gaussian smear.->insulators, 1=methfessel,sigma~0.2=default, -5=tetrah+Bloechl
#ISPIN = 2 # Spin-polarized calculation
SIGMA = 0.2
LREAL = .TRUE.
LWAVE = .FALSE.
LCHARG = .FALSE.
IMAGES = 5
LSCALAPACK = .FALSE.
SPRING = -5
I am trying to find the transition state for water adsorption on a mineral surface using VASP. I have optimized the adsorption geometry and final geometry (surface and water molecule around 5 angstrom far apart). While I would like to try C-NEB, I have started with NEB. Using 5 images, I got the convergence. But there is no saddle point, rather energy is continuously increasing from adsorption geometry to final geometry through 5 images. I have created the images using the vtst tools. Could anyone please enlighten me on whether I am making any mistake. My INCAR file is:
# ISTART = 0 # 0=start from scratch, 1=use WAVECAR-file (default: 1 if file exists, 0 otherwise)
ENCUT = 400
NSW = 120
EDIFFG = -0.05
IBRION = 1 # ionic relaxation routine -1:no 0:MD 1:Newton(fast) 2:conj.gradient(safest)
ISIF = 2 # relax ions only
ISMEAR = 0 # 0=Gaussian smear.->insulators, 1=methfessel,sigma~0.2=default, -5=tetrah+Bloechl
#ISPIN = 2 # Spin-polarized calculation
SIGMA = 0.2
LREAL = .TRUE.
LWAVE = .FALSE.
LCHARG = .FALSE.
IMAGES = 5
LSCALAPACK = .FALSE.
SPRING = -5