Dear Justin,<br>Thank you for your response.<br>I have already read your paper and I have tried semi empirical methods ( Antechamber) and QM from Spartan 10 and I can reach results which have consistence with your paper.<br>
But about large molecule like Lidocaine or Articaine I have some problems.<br>You said "QM calculations are the starting point, not the end" but becase my field is Chemical enginnering I do not have basic information of QM to continue my work.<br>
So if it is possible for you please suggest me a book or any reference
which can help me and introduce me methods of elementary quantum
mechanics calculation. It will be really your kind.<br><br>Thanks a lot in advance.<br>Parto Haghighi<br>