# How do I identify an oblique surface mesh?

I have drawn three surface meshes from a hexagonal material for the $$(0001)$$, $$(1\bar{1}00)$$ and $$(1\bar{1}01)$$. The first one would be the top horizontal surface of the hexagonal structure, the second a vertical rectangular surface from one of the walls, and the third one would be a rectangle at an angle to intersect the c-axis.

But does this mean then that this last one is oblique because it is inclined to intersect the c-axis? How do I identify an oblique surface mesh?

The definition I have been given for an oblique surface mesh is that "it doesn't have a $$90$$ degree angle between the basis vectors." but what are the basis vectors? Are there the $$a_1, a_2,a_3, c$$ vectors? If so, aren't these always the same independent on the surface of the crystal?

I believe that these meshes are rectangular but I am not entirely sure and would like to know if there are any sources I can check to learn the subject better.

• Hi, it would be helpful if you could post images as well. Nov 29 '20 at 14:29
• Unfortunately I do not have any, but I am basing my understanding it from an hexagonal structure shown in the following link : researchgate.net/profile/Sirona_Valdueza-Felip/publication/… Nov 29 '20 at 14:31
• The surface is equal to the one present on te right hexagonal structure on figure 3.24 on chegg.com/homework-help/… Nov 29 '20 at 21:45
• @HitanshuSachania Are the links provided by the user sufficient to help you try to answer the question? This question has gone unanswered for about 3 months and I'm trying to help shorten the unanswered queue! Feb 28 at 5:25
• @NikeDattani sorry, don't have the expertise to answer this question. That was only a general suggestion. Feb 28 at 18:12