num_topics = 8

lda_model = gensim.models.LdaMulticore(corpus=corpus,
                                           id2word=id2word,
                                           num_topics=num_topics, 
                                           random_state=100,
                                           chunksize=100,
                                           passes=10,
                                           alpha=0.01,
                                           eta=0.9)