Alchemy - List of craftable potions with multiple effects

Is there a complete list of the ingredients that can be used to craft potions with multiple effects?

I have seen complete lists for ingredients and effects but I would like a smaller list of only ingredient combinations that result in multi-effect potions/poisons.

If such a list does not yet exist, I could create it based on the other lists. But first I would need some clarification on what happens if two ingredients share more than two effects, or if they have both a positive and a negative effect.

For example, both Dwarven Oil and Taproot have the exact same effects: Weakness to Magic, Fortify Illusion, Regenerate Magic, and Restore Magicka. When they are combined with Alchemy, does the resulting potion have all four properties (even though one is negative and the rest are positive) and if not what does this result in?

Dwarven Oil and Taproot have the exact same effects: Weakness to Magic, Fortify Illusion, Regenerate Magic, and Restore Magicka.

If you create a potion from these ingredients, it would have all four effects (3 positive, 1 negative). With the Purity perk, the negative effect would not appear. As a potion, you can drink it.

If you create a poison from these ingredients, it would have all four effects (3 positive, 1 negative). With the Purity perk, the 3 positive effects would not appear. As a poison, you can put it on your weapon.

I've created a potion "calculator" which you can use to see the result of combining various ingredients.

Here you go, this spreadsheet shows all the possible combinations and you can easily filter it to show only the 4 or 5 effect potions. Sadly, even though 6 effects would be possible, there aren't any valid potions like that.

https://docs.google.com/spreadsheet/ccc?key=0AtdL1GrYQUbldE5PUmlQT1JOYUVaUkk2TkFqMzBzSnc

I found the alchemy section of SegmentNext's crafting guide very helpful. In addition to explaining how ingredients combine, it lists each possible effect, which ingredients provide them, and how strong they are.