Yes, there are quite a few. Some fanfictions explore Harry forming friendships with Slytherins in unique ways. For example, in some stories, they bond over shared interests in potions or a mutual understanding of the pressure they face at Hogwarts. These friendships often lead to new alliances and help break down the traditional house rivalries.
One common theme is the breaking of house stereotypes. Harry and the Slytherins realize that they are not so different after all. Another theme could be redemption, where Slytherins who were previously seen as 'bad' are redeemed through their friendship with Harry. Also, the theme of unity, as their friendship can bring the different houses closer together at Hogwarts.
There's also 'Harry and the Slytherin Alliance'. This fanfic focuses on Harry forming an unexpected alliance with some of the Slytherins. It has great plot twists and turns as they face common enemies together. It's full of action and intrigue as they work towards their goals while dealing with the prejudices of the wizarding world.
In some fanfictions, Hermione might befriend a Slytherin who is an outcast in their own house. Maybe this Slytherin doesn't believe in the pure - blood supremacy ideals that some of their housemates do. Hermione, seeing their different perspective, decides to reach out. Their friendship then causes a stir among both Gryffindors and Slytherins, but they don't let it stop them from growing closer.
One great fanfiction could be 'The Slytherin Bond'. In this story, Harry realizes that not all Slytherins are bad and forms a unique friendship with a group of them. They end up working together to solve mysteries within Hogwarts that the other houses are oblivious to.
A great fanfiction could involve Hermione befriending a Slytherin during a wizarding war - related event. For example, they might be on opposite sides initially, but when they realize the true nature of the conflict and that they both want peace, they become friends. Their friendship then serves as an example to others that the house divide doesn't have to be so rigid.
One way Hermione could make friends with Slytherins in fanfiction is through shared academic interests. For example, in the wizarding world, potions is a complex subject. Hermione is known for her academic prowess, and there are surely Slytherins who also take pride in their potion - making skills. If Hermione were to collaborate on a difficult potions project, it could be a starting point for friendship. She could also show respect for their house traits like ambition and cunning. By not dismissing these traits as negative but rather understanding how they can be used positively, she could build bridges with Slytherins.
One great example could be 'The Slytherin Connection'. In this fanfic, Hermione starts to bond with Slytherins over a shared love for ancient magic research. Another is 'Green and Brave' where she befriends a Slytherin who is also an outcast in his own house because he doesn't believe in the pure - blood supremacy. There's also 'Snakes and Badgers' which shows how Hermione forms a study group with Slytherins and they gradually become friends as they help each other with their studies.
A really interesting plot could be Hermione joining a Slytherin - led secret study group. In this group, Slytherins are researching some ancient and forbidden magic, not for dark purposes but out of pure academic curiosity. Hermione gets invited because of her reputation for knowledge. At first, there's a lot of tension as the Slytherins are not used to having a Gryffindor among them, but Hermione's eagerness to learn and contribute breaks the ice, and they become friends as they uncover the secrets of the magic together.