Pardon me. I am from Malaysia. I thought Chang'an is the old name for present day Xian. If so don't you think it's better to use the name Xian to avoid confusion.
Yes, Chang'an is the old name for present day Xian. But sometimes, we use Chang'an in some special situations, such as some particularly poetic activities. This doesn't matter, you just need to remember that it is called Xi'an now.
