What are the grounds for discipline for an attorney's failure to communicate with clients?

An attorney's failure to communicate with clients and failure to use his best efforts and reasonable speed to accomplish the purpose for which he was employed are grounds for discipline. ¹⁴ (Van Sloten v. State Bar, supra, 48 Cal.3d 921, 932, 258 Cal.Rptr. 235, 771 P.2d 1323.) "Such a failure is a breach of the duty owed [50 Cal.3d 1155] by an attorney to each client." (Matthew v. State Bar (1989) 49 Cal.3d 784, 791, 263 Cal.Rptr. 660, 781 P.2d 952.)