Clan XP

Clan experience was introduced in the February, 2015 update. Clan XP is earned by participating in Clan Wars. Participating in Clan Wars (for the clan) will give the clan a certain amount of experience which you can use to give the people in your clan new perks. Ex: increasing the maximum war loot storage.

Getting 40% of all possible stars gives 10 Clan XP

Getting 60% of all possible stars gives additional 25 Clan XP (35 XP total)

Winning the war gives 50 stars

How to get clan experience
First of all this is an initial observation, there is no conclusive data on this. But from a screenshot I could not upload, it is possible to guess what are the main points which provide exp in clan war. The war in question was a 35 vs 35 (final result 104 - 90) and this is what was shown on the aftermatch screen:

What to understand out of this table:

1. Destroying an enemy base in Clan Wars (getting at least 1 star) gives additional Clan XP based on the enemy player ranking:

2. ??

3. ??

4. Winning war provides +50 clan XP.