Sir, I am facing a different convergence problem. My complex was converged for Maximum force and RMS force in DFT using Gaussian at the 45th step when using the SDD basis set, and then remove from convergence after 20 steps. Now, 183 steps have been completed but the complex is not fully converged yet. Still, Is there any chance to be converged fully again? I have checked the values of the Maximum force and RMS force: it is not decreasing gradually, instead moves back and forth in alternate subsequent steps. What should I do next?
*Increase the maximum number of optimization steps*: If the geometry is close to the correct structure, but just needs more time to settle into the global minimum, then increasing the maximum number of optimization steps may help. You can set this in the input file using the MaxStep keyword. *Use a different optimization algorithm*: Sometimes changing the optimization algorithm can help to get out of a local minimum. Gaussian offers several optimization algorithms that you can try, such as the BFGS or LBFGS algorithms. *Try a different basis set*: The basis set you are using may not be well-suited for the particular geometry of your complex. You can try using a different basis set and see if that helps. *Check the starting geometry*: If the initial geometry is far from the correct structure, then the optimization may not converge properly. Make sure that your starting geometry is reasonable, and consider running a preliminary optimization with a lower level of theory to get closer to the correct structure before running the full optimization with the SDD basis set. *Consider using a different software package*: If none of the above suggestions help, you may want to consider trying a different software package to see if it can converge the optimization. Different software packages use different algorithms and may have different strengths and weaknesses for different types of problems.
I tried to optimizd a molecule and a severe error 2070 arrived which was solved but making the memory 1024Mb and shared processor to 1 but while calculating the frequency i had a problem with negative frequency and when i tried to recalculating frequency to manual displacement of 1 the same error arrived again and it wont be solved even by changing the memory and processor and now i dont know what to do can anyone help me
please how do i solve this error in my gaussian calculation "severe error message #2070 the processing of the last link ended abnormally. all processing has been aborted.
I already performed opt+freq calculation on the molecule. In an attempt to perform single point energy calculations for NBO, I got the above error message
@@quantumguruji please explain. I don't understand what you mean by poor input structure. Is it in terms of basis set? Geometry optimization? Or didn't I draw it well? I was able to do geometry optimization and frequency successfully and got HOMO and LUMO values. I have issues with single point calculations
@@israelekoro8617since you have already optimized the geometry and also performed frequency calculations so there should not be any issue in just single point calculation....check your input geometry and parameters
gauravjhaa.blogspot.com/2024/03/gaussian-common-errors-and-solutions.html
highly commendable. very compact. thank you
Very informative...🙏
Very knowledgeable
Sir your videos are very helpful, please do a video on finding transition states
Sure, keep in touch. Thank you.
I also worked to find transition states and calculated Gibb energy profile
when I try to use the MO edit tool in gaussview, the box came empty and shows, "no MO available" message. Please help me to solve the problem.
Check your input Structure.
Sir, I am facing a different convergence problem. My complex was converged for Maximum force and RMS force in DFT using Gaussian at the 45th step when using the SDD basis set, and then remove from convergence after 20 steps. Now, 183 steps have been completed but the complex is not fully converged yet. Still, Is there any chance to be converged fully again? I have checked the values of the Maximum force and RMS force: it is not decreasing gradually, instead moves back and forth in alternate subsequent steps. What should I do next?
*Increase the maximum number of optimization steps*: If the geometry is close to the correct structure, but just needs more time to settle into the global minimum, then increasing the maximum number of optimization steps may help. You can set this in the input file using the MaxStep keyword.
*Use a different optimization algorithm*: Sometimes changing the optimization algorithm can help to get out of a local minimum. Gaussian offers several optimization algorithms that you can try, such as the BFGS or LBFGS algorithms.
*Try a different basis set*: The basis set you are using may not be well-suited for the particular geometry of your complex. You can try using a different basis set and see if that helps.
*Check the starting geometry*: If the initial geometry is far from the correct structure, then the optimization may not converge properly. Make sure that your starting geometry is reasonable, and consider running a preliminary optimization with a lower level of theory to get closer to the correct structure before running the full optimization with the SDD basis set.
*Consider using a different software package*: If none of the above suggestions help, you may want to consider trying a different software package to see if it can converge the optimization. Different software packages use different algorithms and may have different strengths and weaknesses for different types of problems.
@@quantumguruji thanks a lot sir
please open log file save as a new gjf and add maxstep=5 then submit
I tried to optimizd a molecule and a severe error 2070 arrived which was solved but making the memory 1024Mb and shared processor to 1 but while calculating the frequency i had a problem with negative frequency and when i tried to recalculating frequency to manual displacement of 1 the same error arrived again and it wont be solved even by changing the memory and processor and now i dont know what to do can anyone help me
please how do i solve this error in my gaussian calculation "severe error message #2070 the processing of the last link ended abnormally. all processing has been aborted.
I already performed opt+freq calculation on the molecule. In an attempt to perform single point energy calculations for NBO, I got the above error message
@@israelekoro8617 The problem is in your input structure. You can design your input molecule properly. This error is due to poor input structure.
@@quantumguruji please explain. I don't understand what you mean by poor input structure. Is it in terms of basis set?
Geometry optimization?
Or didn't I draw it well?
I was able to do geometry optimization and frequency successfully and got HOMO and LUMO values.
I have issues with single point calculations
@@israelekoro8617 you didn't draw well
@@israelekoro8617since you have already optimized the geometry and also performed frequency calculations so there should not be any issue in just single point calculation....check your input geometry and parameters