For SPRING=0, the nudged elastic band method is used[52, 53]. In the nudged elastic band method each image is only allowed to move into the direction perpendicular to the current hyper-tangent, which is calculated as the normal vector between the neighboring two images. This algorithm keeps the distance between the images to first order constant. wiki.bnl.gov If the forces are high, and stay high, it could be a result of the small radius of convergence of the LBFGS (IBRION=1) method, due to how it is coupled to the NEB in vasp. Using IBRION=3 and a small POTIM=0.01 is generally a safe and quick way to bring the NEB forces down to the 0.5 eV/Ang range. Jul 26, 2011 · The nudged elastic band approach for identifying transition-states is implemented in Quantum-ESPRESSO and in the latest version, 4.3.1 (as of initial writing, check back for revised instructions), it can be driven by electronic structure results from either CP or PWscf.